Am I overreacting?

It’s a really long complicated story/situation/relationship...but I’ll sum it up.

Me and my ex met and got together in 2018, we’ve been on and off countless times. In 2019 we broke up again and he got his ex pregnant. I found out from his moms Facebook and he told me he didn’t want this to ruin “us”. He’s been living with the girl in the apartment they share but he claims and swears up and down that they’re not together EVEN WHEN this girl is showing something different on social media and his actions make me feel different. He keeps telling me that their lease is up in November and he’ll be getting his own place. They recently had the baby and he didn’t even tell me, I found out on social media. We’ve even hung out since then and he still hasn’t told me. We’re not together right now but he says he wants to be with me and the circumstances will get better. The problem is....he wants to continue having constant, regular sex with me but I don’t wanna keep doing it with someone who hasn’t committed to me yet and when I explain that he gets mad and tells me that “commitment will come in time” so I told him that sex will come in time too. I just don’t wanna be stupid again and get hurt and I don’t know what to think of the situation with him and this girl. I’m conflicted as I really do love him and want things to work, but i don’t wanna be taken advantage of and idk what to believe anymore.