Falling for your Friends with Benefits partner

So this guy and I have been talking since August at first it was supposed to be a one night stand but I realized immediately after that him and I just "clicked" to well for me to just brush him off like he's nothing...I tried so hard to and finally said screw it if I get hurt I get hurt right no big deal? Well here we are December 1st almost 4 months later and him and I have spent almost every single day and night together. I spent Thanksgiving with his family, we are constantly together and if we aren't we are coming home to one another, we are more than friends with Benefits but he refuses to call it a relationship partially cause he is moving and partially because I think it sparks from him screwing things up with his ex in the past that he was with for two years. We are basically in a relationship without calling it one...how do you tell someone you love them and want more from them when you're afraid they are going to be mad..? Or bring up that you were supposed to just be friends with benefits? I feel lost I want to tell him I love him but due to the past 4 guys rejecting me I'm afraid to