[Solved] Mediation and general advice please

Hi , I'm new to this forum and to be honest I should have done something about my situation far sooner than now.

I have a 3 year old son but his mother and I split before he was born. I've tried to be the best dad from the very start and go to all the scans and anti natal classes etc. Since my boy was born I've always been there for him and probably shot myself in the foot early on by still going out as a 3 for family days out. Our split before he was born was her choice but to be honest I also felt it was the right decision too. However she had said after the birth that she had made a mistake and wanted to get back together. I didn't feel the same and felt my boy didn't know any different and I was happy with the separation. We remained friends and did what was best for our boy. From when he was about 8 months I was allowed overnight access once a week and I saw him a lot during the week.

My first problems started in 2013 when my son was about 14 months when I started dating a girl . My ex found out about this on a weekend I was meant to have him and refused to let me have him. She later said it's either my boy or the new girl I was dating and that I was choosing a girl over my son. Her jealousy continued to her accidently adding her on Facebook. During 2 months dating the girl my ex did continue to let me have my one day a week but made everything miserable for the rest of the time and hard work. I finished dating the girl purely on how miserable I was because of the situation of my son. After I did this things became friendly again.

Fast forward to 2014 things had been friendly again and I saw my son even more. I was seeing him every other weekend and every other Thursday. I moved closer to where he lived and things were great. Until I meet a girl in Colombia in June 2014 and my ex eventually found out about this. I had a holiday booked to butlins for him which she stopped me taking him and I told my ex I had lost a load of money for nothing and suggested I reduced her matainanece for a few weeks until I recouped some money that I had lost . She then got the CSA. Involved and shot herself in the foot as she would have got less. I didn't want to affect my son so I still continued to pay what was verbally agreed. Along with half of swimming lessons, football etc. The girl from Colombia came to visit in October 2014 and Xmas 2014 where my ex refused contact the whole time . She let me see him for an hour boxing day but at her house. As soon as Maria went back to Colombia she started being nice again.

I visited Colombia June 2015 and Maria and I got engaged. My ex found out about this and remained nice about things. Maria lives with me now and we are due to get married in April this year . I'm 33 and Maria is 22 and she seems to have a slight jealousy for my love for my boy. Maybe from being young or maybe from being an only child. However my boy has taken quite a shine to her.

And now the very worst part. Maria and I had a big row. It was weekend I had my boy and suggested we go and do something together like visit the zoo. She's rolled over in bed and said we can do all that when we have our own kids which really really hurt. I left it as we had my boy in the other room but text her after leaving home and said that is was a pretty shitty thing to say. Things were a bad atmosphere the whole day until an argument broke out the next day. I tried to keep it away from my son's ears but Maria went into where my boy was sitting and said I hope you don't turn out like your dad to him. She threw a couple of pillows and I didn't want it in front of him and pushed her out the room. Which was a bad choice. She left the house and called the police . I took my boy out for the day and dropped him off at his mums at around 6pm. I had no idea where my fiancee was but I received a call from the police around 7pm and voluntary got arrested and thrown in a cell. During 17 hours under arrest I had an asthma attack and was taken to hospital at 2am in the morning. It's turns out my ex's best friend was in the same [censored] waiting room! Obviously she was always going to tell my ex. It turned out that all charges were dropped and things were made up with Maria and I. My ex during this time had obviously found out as she was calling my brother over and over to try and get info. She didn't even ask me what had happened but as it was her birthday she kept texting friendly texts when was I taking a Amazon gift card round from my boy for her birthday. I'm stupid doing this but I just want a stress free life. After I posted this gift card she text me the next day saying she knows what had happened and she was stopping access until I had a court order. She said she was concerned for the atmosphere my boy was witnessing and from the advice she had received was to safe gaurd him. Maria had gone to see her and said it was an argument that was blown out of proportion. But all my ex did was bad mouth me but said she didn't intend me to stop seeing him but was trying to cover herself with a court order which I don't fully understand her reasoning. I appreciate any concern for his safety but I feel she's grabbed an opportunity with both hands to be controlling and throw a spanner in the works.

This week I've seen a mediator on my own who was actually quite nice about things. I'm shocked that my ex has accepted to attend her appointment next week but feel she has some hidden intentions. To maybe drag it out or to cost me more money as she gets legal aid. Or to try and make herself look better. Maybe she things she has to do it also to get a court date booked.

Sorry for the long post but I thought I should say the history of events. I haven't seen my boy in 6 weeks and I'm in bits. If she doesn't intend for me to stop seeing him then I don't get her motives. Should I just get this mediation certificate and take it to court asap? Or should I wait and see what happens with her appointment?.

Any opinions or advice are gladly welcome