Should i break up with him ?

[Efrain]

We have dated for two years . In the begging of our relationship I found out he was talking to a girl about sex. He never mentioned it until I seemed it on Facebook. I felt so insecure about my self. They talked about when they had done it before we got together. He never replied. But once I called him out on it he told me he knew what he was doing was wrong so he stop talking to her. But I was still insecure. I decided to break up with him , he begged me not to do it. He said he has been faithful but I needed time to think. When we broke up like a week later some other guy cheered me up an he asked me out I didn't know what to say but I said yes. I still had deep feelings for my ex an all I ever did was think of him. So they guy I got with left because I was always upset. I went back to my ex an we started talking again he told me he missed me an wanted to be with me. So we got back together. We were happy he made me happy. But now idk if I'm ready for a serious relationship we been together for two years . I told him I felt like I need time to myself to think about it but he doesn't want to do that he rather work things out together but idk what I want . He's really upset an been pretty depressed when I told him i wanted have time to myself. He is basically begging me not to leave. Also he has been 100% faithful to me an he's says he is still in love with me. He doesn't talk to any girls besides his co workers an has no girl friends. He wants me an only me. The thing is idk what I want, I love him so much but I just need time to think about what I want. I dont want to see him hurt