Help??

I kinda need some advice here. So me (17) and my boyfriend (19) have been together for almost 2 years and we have a 1 month old daughter.

So a while back (around Feb of 2020) my boyfriend downloaded Tinder and was messaging a bunch of girls, and then March of 2020 he was always super grumpy and we literally fought 24/7. Then things got better, like a lot better it was like the beginning of our relationship again when everything was good and we were all happy and stuff. Then June 2020 I found out I was pregnant. It was almost like a switch had flipped with him. He started getting verbally abusive, and he was extremely grumpy around me and would hardly talk to me. Like he would come over and just sit on his phone (like I wasn’t even inviting him over he would just come over) and ignore me until he went home at night. Then around August I noticed he had downloaded Match (like the dating app). And then around November or December I found out he had asked one of his girl friends (you know, the one he told me not to worry about) for nudes, and she sent them. I never talked to her to get her side of the story to see if she was under the impression we were broken up or what. But anyways, I gave birth in February, and ever since then he hasn’t done anything to help out. I’ll ask him to take our daughter for a little while so I can have a rest and try and get some sleep. But then every time she falls asleep for even a couple minutes or she cries he’s handing her back to me for me to deal with it and take care of her. Not to mention he’s always making sexual comments about my body and when I was trying to breastfeed he would be very unsupportive and tell me that we should just use formula (which at the time made me really upset cause I really wanted to breastfeed) and he would just make breastfeeding very sexual and say stuff like “Oh I wish I could have some” and “oh she’s lucky she gets to see your boobs”. And then today in the car we were joking around and he made a comment about wanting to have sex and I told him my doctor said no sex (just as a joke cause I said i was fine with waiting until I got my IUD) and he said “We never have to have sex again” and then under his breath kind of I heard him say “I’ll just have it with other girls”.

And J feel like I’ve given him more than enough chances with cheating (even though he thinks asking for nudes isn’t cheating (In my opinion it is) and being on dating sites is just super disrespectful if you’re in a relationship) and with the lack of help I’m getting from him and all I kinda wanna break up with him. But he’s moved in with me and my mom so idrk how to do that.