Elle,
I remember when I first discovered my parents werent perfect. I was devastated. Its just a part of life. They are people too and make big mistakes. I understand where your obscession and insecurity comes from. I think a good therapist could probably help you immensly and maybe some good self help books. You need to find a way to heal the hurt and forgive your father. It hurts us when we see others, especially family, hurt eachother.