MrF, hope this morning finds you less low. In addition to all the excellent advice above, just a few from experience: not all families are nice. we are sold a myth that family is brilliant, will never let you down etc etc. It's a bastard myth. Many families are nice, but there are plenty who aren't. You and I were dealt the latter by fate.
When you find people you can talk to in confidence regularly about your feelings, you'll eventually come to realise that you were the innocent bystander that got caught up in the mayhem wrought by family. You did not cause it and you aren't responsible for their reactions. So they need to be left to deal with life in their own ways.
You have given your birth family your best shot, and in getting better you might find that not seeking their approval or company works better for you. As you progress through life you come across people you like, and who like you, and these become your real family.
So hopefully today will be day 1 of a new outlook, with the new outward-facing MrF taking the time he deserves to sort his head and heart out with lots of help and support, chemical, psychological, and through proper friends.
That remark of Hangman's about a dog is actually very important: something other than the self that requires care and attention is a great distraction, and while the hands are distracted the subconscious sorts through the serious stuff on its own.
Other approaches might included joining a class to do something that interests you - might be art or kick-boxing, but it gives an alternative focus that means you aren't sat alone being unhappy.
Let us know how you're getting on, allow yourself to be sad and mourn the rotten experiences but then let the mourning pass and be replaced by feeling better.