My boyfriend (20) and I (19) have been together for three years. We really do love each other and so we decided to have sex about two years into our relationship. First things were great, but a few months after we had been having sex regularly he changed his mind. He said he liked me better when I was innocent and that he hated what we did. He stopped all those cute romantic things like telling me I was pretty and writing me love notes. No matter how hard I try, I can't get him interested in me again. He used to tell me he was going to marry me and we always talked about the future and everything but now he just says he doesn't know what the future will be. Obviously, had I thought this would happen we wouldn't have had sex in the first place but since I'm stupid... we did. What do I do? To call it quits after three years is just too much for me to handle... but I can't live like this anymore. HELP!

Why do I have hormones, and why do they make me give into temptation?