I am so sorry for your problems with your family. I have similar issues in that I resent my deceased mother and haven't spoken to my twin sister for 9 years because she totally threw me away after our parents deaths. It bothers me quite a bit and I think about it almost every day.
Sometime I feel like my sister has no remorse at all for just disowning me as her sister so I asked my pastor's wife how it is that bad people can treat other people badly and just walk all over them in order to get what they want. I didn't understand how these people can hurt others yet continue to be successful and happy and even with their dying breath they can ask for forgiveness and be forgiven. It just didn't seem fair to me. But the pastor's wife told me that it's not my concern. I just have to be content to know that God will handle things his way. That simple answer was a lot of comfort to me. It's the same thing as "let go, let God".
I'm not sure that I could ever forgive my sister for what she did to me.....and I'm sure that she couldn't care less. I just have to be able to live with it and knowing that it'll work out in the end makes it tolerable.
HTH
