J.S.
My parents had a similar arrangement but only one of us was still living at home (my younger brother). My younger brother never slept at my mom's house (she moved out). We saw her only at the house... it was really really weird (I was in my early 20's). After a year, my parents got remarried and are still married today (almost 20 years later).
My thought is - don't rush into anything. My parents divorced and had they just sought counceling and separated for a few months it would have been better. In their case there was someone else involved... I never met him or really knew any details... I didn't want to know about it. BUT they got past it and are working on almost 40 years of marriage at this point.
If he's at the house, you are not going to get past this very quickly. Think about a separation - and get into therapy.