Okay laidies. Relationship advice.

I'm really in need of some advice. I'm at a loss for what to do. My SO and I have been together off and on (we've split up twice both times me leaving him) for a year. We are now expecting our first child together but things aren't good. They haven't been for quite sometime. There's a lot a fighting. Almost daily over stupid petty things. We're having real trouble with trust issues do to unfaithfulness on his side and I don't know if I can take it anymore. I don't feel happy like I use to but I do still love him... I'm at a loss because I don't want to leave him for the kids sake and because I truly do love him... Any advice?