I agree with Zenobia - you should both seek some kind of (outside, impartial) help for your situation. My husband and I went through a similar experience, and I was on your end of the situation.

My husband's behavior definitely put our relationship at risk, and I even left him (we were legally seperated for a year and a half), but, eventually, I decided that there was hope left in the relationship. Things have never been the same since, and trust is still a big issue, but I felt that our relationship was worth the effort - as did he. We have been married for nearly eight years now, and it's not a perfect relationship, but we both work to keep it intact.

Hope that helps somewhat.

Do take care.