Not close and have no bond no more with Hubby

I've bee with my hubby for 5 years and married for 6. We used to be so close and so in love and have a great connection but for the past year or two we have been so distant. He has been talking to other girls as well and he carrys on doing so even after I catch him and he promises he won't again, he even met up with one of them twice 6 months ago. We have a 3 year old old DD and I'm currently 8 wks pregannt with our second, which is a miracle because we barely have sex now because they just isn't nothing there even in bed, it's like he just rolls me over gets his way then get of me. I just dunno what to do. I want to leave but I dunno what's stopping me. He is a proper mummy's boy as well and his mum is constantly interfering he isn't working at the moment and he spends all day every day at his mums or sisters while we (me n dd) are stuck at home. Even this baby he isn't interested in he more interested in his sisters kids or the fact she going on a religious pilgrimage. I dunno I'm just tired of trying and caring I just wanna be happy...