Flower, my heart goes out to you and I send you big hugs. If you were my child you'd have everything you need. I wish I could help you.

The solution seems to be to live on your own so that you can get disability. You certainly sound like you qualify. Your parents are not mentally healthy themselves and, therefore, not fit to take care of you.

Are there social services that can assist you with independent living and getting on disability? That's the route I'd take. Also, take full advantage of the UK's medical system. You're very lucky to have access to such health care.

Good luck.