Do I have a right to be upset? or am I over reacting?

Me and my boyfriend split up. We have a kid together and one on the way. He got a new girl a few days after we split and ever since he hasn't given a damn about the kids or me. He promised me he'd come to my appointments with me still and be a really good friend. But he missed my ultrasound today because he was out all night with his new girlfriend and over slept. or so he claims. (I told him a week before the appointment when it was and reminded him the night before) im pretty upset about it. I also thought hr would definitely come because he hasn't seen our daughter in a few days and I thought he'd want to spend a few minutes with her. But no.... Am I over reacting? I messaged his mom about him missing and not seeing his daughter and she used me breaking up with him as an excuse. She said "well you did make it very clear that you didn't wanna be with him anymore" SO? he can still be a fucking father together or not. Shes been defending him since the split. She tries making me out to be a bad mom but im always with our daughter 24/7 even when we were together I did 98% of it all. I snapped om her. I said "You know you guys are so fucking blind to think that he cares about his kids at all. But he hasn't made an effort to see them at all. I think you need to open up your eyes and realize which one of us is the bad parent because it sure as fuck isn't me. I'm the one taking care of our daughter and he's the one running around acting like his childern don't exist" I've made mistakes im young (just turned 20) but im not where near a bad mom. at all. I love my kids more than life itself and my actions actually prove it unlike his. I'm just sick of him not being a father. I could care less about his new chick if he didn't put her first over his kids.