[Solved] Cohabitating...

Firstly, I'd like to introduce myself as this is my first post here...

I'm Dylan, 37yrs old, in a rut and in need of some help/advice please.

Right, here goes... I've been with my fiance for 4 years now. We moved in together a few months after meeting as the lease on my rented house was coming to an end, she was struggling to pay her mortgage on a property shed recently bought and well it just all seemed to make sense at the time.

Roughly a month or so after moving in, she said her mum had recommended getting a legal document written up 'pre nup'in case things went pete tong. And basically extinguish any rights I may have towards her assets but in particular the property.
She gave me a copy to read through and it basically started what mine was mine and vice versa and in the event off a break up that's how it would stand.
It then stated that upon getting married everything would be 50/50. In all honesty, it wasn't a problem signing it and I didn't question it at all. I was happy and seen us being together and possibly getting married in the future,all was good.

Anyway, 4 years down the line, we have a 2 year old daughter together,2 dogs and are living the family lifestyle.

So 4 years on, I've been paying the mortgage and majority of bills as she now only works part time since or daughter came along. I mean I've over 20k into the house in that time and yet she still won't add me to the mortgage deed.
I hate not having any security in my life as she's kicked me or a couple of times 'get out off my house' is the usual line and it's really hit home that I leave with a bin bag full of clothes and that's it! I'm37 now and it'll be to late for me to get a mortgage of my own soon.

Whenever I bring up putting me on the mortgage, she just turns nasty and we fall out. She has zero intention of doing this. I Just feel like a lodger now and that im getting taken for an absolute mug.
I have no rights to anything after signing the pre nup and I have to just keep paying thousands of pounds a year off her mortgage and yet she can kick me out at the drop of a hat and I leave with zilch! Does this sound as messed up to anyone else? And that she's being totally out of order? Or it's it just me? I'm so stressed about this, I just need some security but she doesn't seem to give a sh#t. Just pay your money and shut up, if you don't like it leave. That seems to be her attitude.

I'm sorry for the long rant but I'm hoping someone else has been in a similar position? And do I have any rights even though I signed the pre nup? What about the thousands I've paid in? An I entitled to any of that back?

Any help appreciated. Thanks