Are we just trying to re-live the past?

I have a boy friend we have 10 months together. I'm 17 and he is 19. We usually have problems bcuz he is very jealous and he doesn't like it when I dnt dress "decently". We do talk about getting married and about the future but the thing is that Im not sure if I'm going to b happy with him. I have never cheated on him. I truly believed I loved him but about a week ago my "first love" from childhood contacted me. I was so excited to talk to him again because it had been like 4 years since I had last heard of him but I hid this from my bf bcuz I knew he was not going to approve. So I spoke to my first love and I found out i still had feeling for him. He understands me better than anyone and he always cheers me up when I fight with my bf. He lives in another state but he is coming down in a month. I want to see him but I have a bf and I knw that would b wrong. He tells me he still loves me thts why he looked for me bcuz ke never forgot me. I just don't knw what to do. I'm torn between seeing him and lying to my bf. It's not fair for him but recently we have been having a lot more problems bcuz of his jealousy and I don't want to break up with him just to go back with my childhood love. But I don't know how to figure out who I love? What question should I ask myself?