Confusing contact with ex after one month NC?

Hi all, basically its been about one month since my boyfriend of 4 years broke up with me. We are both 21 and he felt that I was holding him back in life. I think he wanted to experience what it was like to be single and be able to sleep with other people - something he craves but never seems to want it for very long before he comes crawling back to me because he realizes it isn't that good (he has left about four time for about two weeks then come back). He feels like he is too young to be in such a serious relationship. In saying that, we love each other a lot, and I know there are things that would need to be worked on for us to be a good couple, such as me being too dependent on him, and him having more freedom in the relationship.

So I have had no contact at all for four weeks, until last night I caved and called him. He answered and I said I was just seeing how he was going and was thinking about him. He was quite cold at first, and we had small talk, then he started to say how much he missed me sexually and how turned on her was getting just talking to me. I tried to change the subject but thats all he could think about, he wanted me to come over, and he also wanted to come over to my place. I said I cared about him too much to have a one night thing with him and that I couldnt give him what he wanted. He then started asking me whether I had slept with anyone else since we had broken up, and if I had he wanted to hear about it because it turned him on. I dont understand why that wouldnt make him upset or jealous or angry to think about? Once I was firm about my answer, he started to be a bit rude to me and said that he was talking to other girls. We got off the phone and he texted me saying it was best I didnt call him again because it messed with his head. He then deleted me off all social media.

I am really confused and I don't understand what's going on or where his head is at. I really miss him and I will keep giving him as much space as he needs because I know it would be toxic for us to patch things up right now, but I dont know where to go from here. Any help or advice would be appreciated