Falling out of love?

First I want ask no one to be rude or to come for me, im having a really hard time trying to understand my feelings. So my fiancé and I have been together 2 years, and we had our baby 4 months ago. He’s verbally abusive, but not all the time, and he has a bad temper, but he is a good guy and I do love him. My ex and I have been split for 2 1/2 years, and I don’t think I ever really got over him, I think about him very often, and we talked today (my fiancé gave me permission, it wasn’t to talk about our past relationship either.it would take me too long to explain what it was for) and I really do miss him. But he also has a baby now, as do I. And I am forever greatful we split because I have my beautiful baby bc of it. For a long time now (about the time I got pregnant) I have been thinking hard about my present relationship. I don’t think I want to marry him or spend the rest of my life with him bc of his bad temper and bc he’s cheated on me (he didn’t have sex with the girl though.) so I don’t trust him at all, but I love him a lot and he’s the father of my child and it would tear me apart to end things with him, especially bc my baby wouldn’t have her parents together. not to mention I’m a SAHM with no money or vehicle of my own. I love my fiancé but I don’t think we are meant to be together forever but on the other hand I think maybe we are and I’m just overthinking things too much. Idk what my question is, I just needed to vent I think.