Hi Avaa,
I have read your letter over twice. You have suffered from what I call 'rubbishing', and you have been very strong to get through it. It is the persistent nature of this cruelty, when we are looking for love and approval, that messes so many young people up.
I think that a counsellor would be really helpful for you, and it will probably take a long time for you to accept just how deep this hurt goes.
As for your stepmother being a changed person, I would feel uncomfortable about that. I can sense the manipulation even through your one post (the thing about the 'grandbabies'). Polite but cautious would be my advice. I know I'm cynical, having been in this type of situation myself, but sometimes you have to be firm with people who haven't earned your respect.
I hope that you have a lovely future, and some happy children. It's your life now, and I think you'll be a good parent because you know the importance of kindness and tolerance, learned the hard way. That's how it was for me, and my daughter is my best friend. I have learned so much from letting her grow up the way she wanted to.
Good luck, Myzen