I agree with missnw. I had the same thought that maybe he was trying to hide his own guilt and sort of force a breakup. If nothing else though, he needs to deal with the reasons he can't trust someone. I agree as well that you shouldn't apologize if you have done nothing wrong.
Depending on the seriousness of your relationship, I would also suggest that couples counseling might be beneficial. It could help him open up a little bit and give you a little more insight into his concerns. Maybe you are doing something, saying something, while innocent to you, triggers something in him that reminds him of when he was betrayed before. Having a counselor help you two could help bring that to the surface.
Good luck!
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