Get Over My Ex Or Get Out!

I need help. Today, my husband gave me an ultimatum. In a nutshell, we met each other when we were both (unhappily)married, got divorsed and just this year he and I finally got married, after 3 yrs of living together. Unfortunately, in the beginning of our relationship, he lied constantly to me. He was living two lives, but assuring me that I was his life and the one he loved. I found about the lies well into us living together and it rocked my world. (To give an example: When we were together - I mean we had already started talking about moving in together, he took his wife and two kids on vacation. Telling me he was there w/ his parents and kids. Even emailed me picture, that of course didn't have her in it. I found this out by seeing her in some photos and year and a half later.) I had always trusted him, and that shattered. Because of this, I have issues with his relationship with his ex-wife. I was so hurt by everything he did to me when she was in the picture, that I am really sensitive. He has a "parenting" relationship w/ her b/c of thier two kids. Sometimes I feel that the ex oversteps her bounderies, but he does not agree. It causes us to fight horribly. After this last fight, he said he wasn't going to deal with my insecuities anymore (even though he admits it was his actions that made me this way) and gave me an ultimatum. Get over it and move on, or he would divorse me. I don't know what to say to him.