Comparing his son to my son.

So my boyfriend and I have been together for 2-3 years and we’re about to have a baby together. I’m 27 weeks pregnant. But the problem I have is sometimes when we talk about stuff he likes to compare our kids. We both have 1 kid from previous relationships. If I say something like oh yeah my son had a speech delay. He would say something along the lines like his son is better, he talked when he was really young etc. yes I understand he wants to show off his sons accomplishments etc but then he tries to say what I didn’t do as a parent and that’s why he’s like that. & when his sons mom get brought up he always compares my pregnancy with hers. For example, I told him I have to go do my glucose screening test and explaining what it was. Then he responded “oh when I was with (name here), we never had to go. I went with her to all her appointments” which made me feel bad because he’s never went to any appointments with me. Even if I told him a week in advance like our 4d ultrasound... I had to go alone. And I rescheduled it like 4 times for him and he always ended up not going because he’s either tired or something else.. I don’t know what to do. He makes me feel like his baby mama and his son are so top notch and he knocks me down and my son sometimes. He doesn’t realize the way he says things. He still gives his baby mamas nieces money anytime they ask for $50-$100. He told me he told them he can’t do it no more because he’s no longer with their aunt but still does it. Yes I understand that he watched them grow etc but when it comes to her side of the family asking for something his answer is always a quick yes and he’ll jump to do it. But when it’s me it’s so hard. And I don’t ask for nothing but his time. (Ex: 4d ultrasound) at this point I feel like leaving him so he can mend his family but I don’t want to feel like I’m over reacting for no reason. I’ll be fine raising our daughter by myself. Idk what to do any advice?