Overreacting or no??

Me and my child's father broke up when I was 4 weeks pregnant (the day after I told him I was pregnant). He was unsupportive my first 6 months of pregnancy but had became more supportive. He has started back dating the woman he was with before we got together and at first I had an issue with it because he was constantly taking her on dates to expensive high end restraunt sbout has yet to buy anything for the baby (I'm 32 weeks now). I was initially upset but I got over it. Now for some reason I just have a negative vibe about him. When he responds to my messages it something quick and then after 2-3 text he stops replying once I mention something regarding needing him to buy or provide something. Our baby shower is Thursday and I kind of just want to cancel it. It hurts to carry someone's life and feel unappreciated.. This isn't an easy job. I feel like I may be becoming depressed. Mainly because of him acting different now that I've accepted him and his girlfriend but also my self esteem is beginning to lower.. I've been nice to him my whole pregnancy regardless of the horrible things he's said to me and done to me during this time and now I'm feeling a bit stupid. 😔 I'm not sure how to shake this feeling.. I don't even want to be around him or his family at this point. Is this overreacting? Any advice?