Still sleeping with baby daddy who doesn’t care

So I’m 7 months pregnant long story short I got pregnant by my guy best friend of 4 years we never dated but would spend a lot of time together when I told him I was pregnant he was fine with it then got scared and ditched us he moved 4/5hours away for “work”and only texts me like once a month just saying how are you and never replies again these last 2 time she’s came into town he’s messaged me and we’ve slept together idk why I do it Bcz I miss him so much and I just wish he’d be here for us but he doesn’t care even when I send him pictures of my ultrasounds updates he doesn’t say anything I feel stupid for letting him use me when Ik he doesn’t respect me but I’m just so sad and just so hurt and feel so lonely in my pregnancy nothing more than I want for him to care for us. I guess I still sleep with him Bcz he brings me comfort sounds stupid asf Ik but idk :/

These are what he texted me these last 2 times but why see me just for sex? I don’t get it I want to think he cares but obviously he doesn’t I found out he had a gf after he moved when I was snooping on his Instagram and I never confronted him about it idk how long they’ve been together or anything . He never mentioned anyone to me and still doesn’t even when I ask about his life it makes me a piece of shit for sleeping with him after finding out on my own that he has someone else and maybe that’s why he’s acting this way Ik he doesn’t owe me anything since we aren’t together but I don’t know what to do my heart truly hurts I feel like he’s using me caring for himself knowing that I want him in the babies life to his advantage and I hate it so much how does he not care about his own son ? I truly feel worthless and I feel like I failed my son already Bcz he isn’t gonna have a father

Any advice or opinions please don’t be mean this is alll so much for me and just so much stress during my pregnancy having to do it all alone at 21