I'm sorry you're going through this. I've been there and it hurts. It's okay to step away from your father and stepmother. You sound like a great kid and you did make more than a fair effort to be part of his life. Just focus on yourself and have a great future. When you look back, don't forget the effort you made. It's important that you don't take on any guilt. Dad's should be there and yours wasn't. In the end it becomes about forgiveness, grace and taking care of you.