Relationship suffering post abortion?

I had an abortion in October and the only person who knows is my boyfriend. I don't really like discussing it or how I feel since, even though he's encouraged me too and I think it may be affecting our relationship. For a few months afterwards I had problems maintaining a ual relationship with him. I was afraid of getting pregnant again (even though I was being more careful with my pill) so was constantly tense and at time it hurt. When I told him about my fears however he told me to stop worrying about it and we'd take it slow. Everything was perfect for a while but recently I decided to come off the pill as my periods are very irregular since the abortion (something they NEVER were) so I told him my decision and said I'd rather if we didn't sleep with each other while I was off it. He had no problem with this but the next night he stayed in mine I practically forced him to sleep with me. He asked several times if I was sure before finally 'giving in'. The next day I felt cheap, like a little tramp that uses lets people use her for so that she can feel loved. This has happened several times since and it's always me that not only initiates it but almost forces myself on him, as the last thing I want is for him to reject me, then I feel like crap the next day. I don't know why I do this as I know he loves me and would do anything for me. How can I get over this?