You were getting such good advice, I didn't think there was much I could add. You have been in my thoughts and prayers. We have this father thing in common, mine never kidnapped me. He did however, convince me to give away my first born, while I was medicated by the doctors who wanted to sell my baby. This being one of the worst things he ever did can't say it is the worst but it has to be in the top three. Somehow karma has a way of taking care of things. My daughter found me, when she was sixteen. To get over all this I just forgave him.
Forgiveness is not for the person you are forgiving, it is for you. Most likely the person you have forgiven will not know or care. Just like they don't care if you stay up all night crying over what they have done to you. Forgiving takes the power you are giving the person away. I have stuck with friends through the worst relationships because while I disapproved of their mate, I felt this is when they needed me most. Your sister may need you now more than ever. It seems as though you miss seeing your father and sister. I would miss my dad. The truth is the truth and it doesn't matter what he thinks or what anyone (including myself) thinks. So when he expresses his opinion I consider the source, and am no longer angered by any of the negative energy he sends me.