What am I supposed to do!?

Dakota
My boyfriend and I have been together for almost exactly a year and a half and we now have a 5 month old son. But while I was 8 months pregnant I found out that he was cheating on me (I found out over facebook so it was even worse) So I left him. Eventually we got back together and now I feel terrible because I'm not sure if I still feel the same anymore and every time we have sex all I can think about is what if he is imagining me as her 😭😭😭 then last night while we were sleeping he was talking in his sleep he said "I love you kassidi" and I was awake all night crying but I don't know how to react to it. I feel like the only reason we are trying to force it to work is for our son...I have no idea if I should leave him or keep trying.