Feeling completely alone

My sons father and I are “working on things” but we do not live together. Our son is 1.5 and I am currently 27 weeks pregnant. We can’t seem to agree on anything. And I mean anything. When he does come over he doesn’t help out with anything. He’ll stay the night like once a week and won’t wake up with our son even though he knows I could use a tiny break. He’s continues to make little comments everyday about something I’m not doing. And is always “joking” about how he needs a side piece. Maybe if I felt like I had a partner I would want to sleep with him. He knows how anxious I have been these past couple of weeks now and I feel like he’s still not thinking about my son and I. He has an older son from a previous relationship and his sons mom is a nurse in the er. He plans on getting his son today and then coming over tomorrow night after he’s gone. Am I wrong for being concerned about my sons and I’d health right now? I don’t want to be exposed to anything if I don’t have to. He doesn’t see it that way and is trying to make me feel bad. I guess I just needed to vent a little bit because I feel so completely alone. I don’t feel like I have anyone on my side. I can’t even talk to him about the new baby because it stresses him out. Not sure what to do about any of it ☹️

And honestly we’re not really doing anything to work on our relationship. We don’t talk because it starts an automatic argument. He jumps through hoops for his oldest son and can’t even help me out with ours. His older son is put in sports all year round but it’s “too expensive” to continue my son in swim lessons. It’s the little things that all add up and make me feel like this isn’t worth it anymore.