That is how it looks to him.

To me, though, it looks quite different. To me, he is completely out of line to blame you for his problems. Besides that, he is looking for a solution in the wrong place. The solution lies in fixing himself, not in endlessly blaming you.

What exactly does he hope to accomplish by insulting and blaming you forever?

I wonder why he stays with you if he thinks that you are a slut no matter what will happen or how much I have or will change... What could he be seeking? Maybe he gets some sort of strange psychological benefit from calling you a slut, criticizing you, and holding your past over you endlessly.

I also wonder how long you will stay with someone who thinks that you are a slut no matter what will happen or how much I have or will change... How many more days/weeks/months/years?