Venting / Advice!!

My boyfriend and I have been together for two years and we recently just had a baby. He’s never cheated on me but I’ve caught him still talking to exes that he said he no longer talked to so I have trust issues with him. After our daughter was born i had really bad post partum and he wasn’t there for me at all. We love 45 minutes from each other and he was in school so he only came to see my and the baby on the weekends but always was leaving to go play basketball and hang out with his friends. Every time i brought you how it made me feel he’d say just cause we had a baby doesn’t mean our life stops. He was going out all the time and barely seeing us. We had an argument and It was the last straw so I broke up with him, almost two months later we got back together. He admitted to me that he was just so angry with me and didn’t want to be with me leading to our break up but now he wants to be together. We’ve been back together for a few weeks and yesterday we had an argument over him liking girls pictures on Instagram and these were girls in our area ( he’s from out of state and was only here 3 months before we started dating and always claimed he didn’t know any girls out here). I knew we were broken up so I tried to let it go but I noticed some like were while we were together so I tried to communicate I didn’t like that. He claims I was trying to catch him in a lie because he already told me he didn’t talk to anyone during our break and told me he’s a social butterfly and is meeting new people and doesn’t like that I’m telling him who to converse with and whose pictures he can like on Instagram. I have no problem with him meeting people but I don’t see why when he’s in a relationship he need to be making friends with random girls when he’s out. Me expressing how I felt lead to him saying that just because he’s meeting people doesn’t mean he’s unfaithful and that it’s always something and I always have an issue and if I’m going to press him so hard about things like him liking pictures he doesn’t want to be with me cause it’s petty and childish. It really bothers me that instead of making me feel secure he just tells me he doesn’t want to be with me. Is it wrong for me to be upset? In the beginning of our relationship he was really insecure and didn’t like me conversing with any males and we both set these boundaries for respect. But since he’s started school he wants to hangout with his friends more and go out and spend one day a week with our daughter and I which i personally feel he should of done and thought of before we decided to have a baby. He’s 23 and I’m 24.