[Solved] Advice on what to do now.

Please please looking for advice and support from anyone legal minded or with social services knowledge.My story is a bit long but it is all relevant information that is needed to be able to advise me correctly.

July 2014 I was out at an all day appointment and left my girlfriend of 5 years at home with our 2 children, our 3yr old girl and 1 year old boy. We had not been getting on too well the last few months.
When I returned from my appointment my gf and the children where not in. I presumed they had popped to the shops. That evening after still not hearing from her I got hold of her mother who lives 150 miles away, to be informed they had gone to her Mum's house and were not coming back. The initial shock of them leaving turned to anger that she could leave and not give me chance to say goodbye to the children or anything.
I met my current fiance in early December 2014. Being with her had given me the support to push for access to the children. I left the flat I had shared with my ex and all of the clothing that was left behind (my ex took nothing when she left) had to be taken to a charity shop. No space to keep the childrens clothing and none of it would fit now.
Right until mid-December my ex would not answer any calls, nor would her mother. I could not get hold of anybody and I tried more or less daily. The mother had moved house just before my ex left and so I did not have their address toturn up at their door.
The week before Christmas my ex finally contacted me. All she would talk about was her new boyfriend and I was "allowed" to speak to my daughter for 5 minutes but not my son. I was told for Christmas the children needed clothes and I sent up £200 of clothing to her temporary address I was given. She also informed me that due to problems, since she left me and went to her Mums she had moved somewhere else and then back to her Mums. Each move , changing my daughters nursery.
She said I could see the children but I had to do all the travelling as she wouldnt. She also said I could only see the children on a set date each month for a couple of hours.
I was not happy with this. I wanted to see the children at least for a full day to start with and overnights eventually. We couldnt come to an agreement and she said I had to agree before I could see the children. She suggested mediation.

In Feb 2015 I arranged and had my mediation appointment. The following week I received a letter from my mediators stating my ex had refused to attend mediation saying she had a social worker now who had told her the children could not handle their dad coming back into their life and to not attend mediation!. I contacted my ex about this. She informed my they had a social worker as they were now living in a domestic abuse hostel (but wouldnt say anything else) and they were going to be moving again and she had too much going on to deal with me.
I contacted her social worker myself who couldnt give me details but confirmed my children and their mum were in a hostel and my son had been under a protection order but would not tell me the circumstances. This was even after confirming I have parental rights.

I agreed I would either take her to court for at least shared custody. However we agreed id give her one chance for me to see the children. This started in May 2015. The visit was amazing,the children took to me like they had never been away from me for 10 months.
The week After the day I spent with the children, I was told at 11pm at night my ex had walked out of her mums house (she had moved back there AGAIN) with the children after a row and was walking to the nearest town 11 miles away to find her boyfriend. My ex wouldnt answer my phone and wouldnt tell me what she was doing with the children that time of night. 3 days later she rang me and said she was not going back to her mums and would stay at various friends houses.I contacted social services who said they would sort it out. My ex actually turned up at her local housing office claiming homelessness. She was told by her social worker shr had to return to her mums house as the children need stable home.

The following few months I had the children various weekends, we me doing all thr travel.
In July,during a visit, my daughter told me that her mums boyfriend had hit her and is mean to her and had locked her in the bathroom for speaking too much!. Brought this up with my ex who said nothing happened.
In August, picking up the children from their mothers house I noticed a large bite mark on my sons arm. I asked what happened thinking it was another child at nursery. My ex said SHE had to bite him to teach him a lesson for trying to bite his sister. When i got home I took photos and called SS. They looked into it and said they had no proof.
The following week I had a text from my ex's mum to say she walked in on my ex new boyfriend with his hands over my sons face and mouth nose and shouting at him to stop crying. She kicked him out the house. Again i called SS who spoke to both children,my ex and her mum. Again nothing came of it!

In September my daughter started primary school. I met with her teacher to introduce myself...after fighting my ex for the name of the school my daughter attended. The teacher had already , 3 weeks into school, noticed my daughter has "issues" with development and behaviour and was arranging meeting with social services to discuss this. My daughters teacher along with their Social worker has decided my daughter needs a school counsellor to have sessions with her which start next week, to help her cope with things and axcess her for ADHD.
My sons nursery manager found out about me last week via my daughters school. I presumed they had my details and they presumed my son had no "real" dad around only the exs partner. The manager contacted me to inform me my son is having issues with behaviour and development and anger (he is under 3yrs old) and he is under a review with multi agenncies

Each time the children stay they laugh have fun smile and play. They scream when its time to go home and my daughter openly says she wants to stay with me and my fiance who both children love. They have their own room at mine, a garden to play in and family members around. They have routine at mine, set nath times, set bedtimes.At their mums they all (my ez, her partner, her mum and the 2 children) live in a small 2 bedroon flat that the windows are kept shut and they smoke non stop inside. Bedtime whenever they want. My son has had repeated chest infections over the past 18 months that make him sick, yet when he stays with us his chest clears. I took him last year to my GP as my ex doesnt take him. The GP did say he would inform SS of the recurrent illness due to the family lifestyle.

Just last week i was told by my exs mum that my ex has been leaving both children overnight at her boyfriends so she can get some "peace" over the past few months. We never knew about this. She had a new baby in December with her new partner and leaves all 3 children with him. Bear in mind he had 2 children removed by SS a few years ago due to abuse. He is living with his sister who recently had 3 children taken into care. This still doesnt stop my ex leaving the kids with them. Even after what he has done to my son.

I have yesterday been told my ex is planning on removing my daughter from school and moving away with her partner. She refuses to answer anyones calls. My daughter is still attending school as I called the school this morning. However they say my daughters attendance is currently approx 60%.

So thats my long long story. I guess there will be questions asked like why have i just not turned up to collect the children and bring them here. Why have i not been to court.
Well, with my ex moving around and only meeting me for children hand over at her local train station, I would not know where to go to get them. When the children are down with us, I understand I could keep them here as there are no residence orders in place. How would I go about this though when my children have nursery and school. Could i just not take them back and register them at school where i live?.
I would love to go to court. Even if it is to stipulate where she lives and to not allow her partner alone with the kids.

My other concern is I am partially disabled and so is my partner. We worry we wouldnt get custody either because of it. We can not find anybody local that could deal with the court side of things with Legal Aid. We have no mony to pay for this upfront however much i want to. Also with our disabilities, what is the court turn us down for even partial residency? Would that make the situation worse in terms of thr mother denying me contact if things still go her way.

BUT...what can i do now? Social workers are fussed and are trying to help the kids cope instead of accepting they shouldnt have to deal with it to start with. How can they not think its wrong my daughter had 4 nurseries in a year and i just about to move to her 2nd school in 4 months. The partners history of abuse and removed children. The reports they even get from strangers informing them of concerns over screaming shouting and the smell of drugs and smoke from their flat. What the heck will make them listen? Where can i find a legal aid family lawyer that can help?

Thank you for reading. Please please no nasty comments. I am a disabled dad whose children were ripped away and are going through so much on top of not seeing me for 10 months.