Are you dating this guy:
http://psychforums.com/viewtopic.php?t=30507
You seem like a really nice person. Sounds like you did some things out of depression, but I do not think that you did anything terrible. I think it must be tough that your boyfriend feels the way he does. You could help him with his feelings, but he is the one that has to come to terms with your past.
It is important that you do not feel any less of yourself. Again you are not a bad person and you did not hurt anyone. Don't put yourself down, and do not feel guilty.
Only thing that I can think of that you can do to try and make him feel better is the following:
1. Tell him that you love him with all your heart.
2. Tell him that why you love him and how great he is.
3. Tell him that you are his with all your body and soul. That you wold do anything for him and that you are 100% devoted to him without reservation and for all eternity.
4. And finally tell him that he cannot do anything to make you love him any less and that you will wait for him for whole eternity if you have to.
I do know if this will work, but that would be what I would like to hear if I was in your boyfriends shoes.