He won't let go of my past

Please help me, I have a dodgy past of cheating and basically being a bit of a tart! This was all in my early twenties but now I am in the 30's and grown up a hell of a lot me.  My SO is obsessed with my past and gives me so much shit about certain things I've done, things I'd rather forget, I am not that person anymore, he makes me feel like I've done all these things to him.  It's like mental abuse with him constantly going on about it, calling me names like slag and stuff like that.  Everytime I think of something I have done I get so nervous! I've started going grey with stress.  Problem is I feel the need to tell him everything I've done, well he makes me feel like he needs to know.  Truth is his past is drug filled where mine was alcohol and a couple of one night stands oh and yes I cheated on various partners.  I look back at my actions and I want to shake some sense into that person!!! Am sat here now writing this with a horrible gut feeling.  Why can't he accept me for the person I am today and stop punishing me for my past, a past he was never a part of.  Please ladies don't give me abuse am really stressed by this and need some serious advice