Collegebeauty - I went and read your profile. It sounds like you are going through a very hard time, on many fronts.
What does your therapist suggest about these encounters?
I would think that it is important, during this time where you are really struggling, to keep yourself out of difficult situations. For example, if an old guy friend/boyfriend wants to get together, keep it in a public area where nothing uncomfortable for you will happen. A group gathering, a restaurant, etc.
I really don't understand your family welcoming your abusive cousin in their home especially while you are there - but since that is happening, I would suggest keeping yourself distant and not becoming involved with punch play fights with him.
What does your therapist say about this? If you haven't discussed these encounters with your therapist, please do. It sounds like you need guidance.
You don't have to accept this. Speak to your psychiatrist but to your family as well. Under no circumstances should he come to the house. Some things are "family conflicts" or "forgive and forget" but as with that crime, child sexual abuse laws now apply retroactively. I don't know legal specifics but I would find out if I were you. There are counseling centers for women who have been abused. And they can advise you of your rights. At this point in recovery, you may not be ready to go forward with pressing charges. But when things are stable I would. Something like that is unforgivable. But whatever you do, make sure to find out your legal rights including at the very least a restraining order. Even if they feel he should be part of the family, that should not be their decision. You are in the right and in allowing him around they are in the wrong. If he doesn't even realize what he did years ago was wrong then I don't have any sympathy for him whatsoever and neither should they.