Should I tell my best friend I'm in love with him?

I'm sure this question is asked all the time, especially when it comes to a girl and a guy being best friends. I've always heard that usually guys and girls can't be best friends because one of them will end up falling for the other. Seems to be correct when it comes to my situation. I'm 18 years old, female, and have started having those feelings toward my best friend.

Recently, I've started having feelings for my best friend. Honestly, I would've never thought that I would ever have these type of feelings toward him or for him. We've been friends for about 8 months now. We do everything together and we're basically together 24/7. He's the only person I tell every single thing to and the one that I trust with everything. I've tried controlling my feelings toward him and tried telling myself that I'm only having these feelings because we're together so much, but that's not the case. I can't control them and the more that I try to control them, the more it gets to me.

The only thing that's stopping me from telling him that I've developed these feelings toward him is our friendship. What happens if I were to tell him I'm starting to "like him like that" and he totally rejects it and then it ends our friendship? Should I keep this to myself? Then again there's that question "What if I don't tell him and he's thinking and feeling the same way?" and then nothing ever ends up happening. So many questions are running through my mind at this point. Someone please HELP!!!