Sex with him

When he and I first met, after a couple of months we started having sex. He was my first, and made me feel extremely comfortable. I was 17 years old. I became a sex addicted we always made sure we had sex at least once a day, if not 4 times. We've been together for 3 years 2 months and 8 days. We had a baby girl last year in December. Since then I have not felt attracted to him what so ever. But to save him some hurt, I have faked liking sex. Have it with him when he wants it. I could go my whole live without ever having sex with him again. I'm such a bad person, but I just can't help it. I'm craving something different, different size, different type, different color. I really want to explore (hope that doesn't make me sound like a slut). These days I don't feel a connection. What could I do or say to make him understand when I talk to him about it? Mind you though, he is not the type of person to just let you break up with him. Kind of controlling. So I'm scared and need help. Any advice?