He cheated

My boyfriend who I thought was going to propose to me cheated with his supervisor at work and lied about it. On my daughter’s birthday I saw him messaging her and because we where broken up at the time I asked him out of curiosity what was going on he proceeded to tell it was nothing and how I’m always accusing him of things he’s not doing. It’s now a month later and he who left me is telling me that he did sleep with her at work and a few other people. When I accused him of lying to me he tried to make it all seem like it was all my fault we where in the middle of making up but I can’t look at him the same way I did before. Baby girls a year old should I suck up my pride for her or should I leave him where he’s at.