Like my best friend, should I tell him?? Please help its urgent!!!!!

I just switched to a new high school this year where I met him. At first we were just friends, but after a few months I started to have feelings for him. I've had crushes before on guys who were cute, but they were superficial on kids I didn't even talk to. This is my first time having deeper feelings for someone (as deep as high school gets I guess) but its killing me not being able to say I like him more than a friend.
Last friday night he slept over at my house and we had a great time. But when he left I felt more depressed than ever. I really wanna tell him how much I care for him, instead of feeling I'm living a lie. He's straight, but maybe if I open up to him he'll still accept me??
He's called me gayboy and faggot jokingly, many times, but it still hurt me thinking of how he might respond if I told him. I'm scared to death of him being creeped out and not talking to me again. I know if he's a true friend he'll stay, but I don't want to go through the pain of being rejected. I already struggle with depression and feeling worthless, I just don't wanna deal with the heartache and loneliness anymore. I really want to tell him. If he accepts me for who I really am I think we'll be closer friends, and I won't feel worried or scared to be who I really am around him. But if he's too uncomfortable with it and I lose him as my only friend I don't know what I would do.
I might not say anything either. If he never finds out I could still cuddle with him under the blankets while watching movies, or call him my boo like I do now without it being awkward. I want to tell him the truth and how much I care for him, but maybe its best for our friendship if I don't. I'm so confused and feel like its hopeless, I've spent the whole weekend crying over my life and why I have to deal with this shit. Please, if anyone could offer suggestions it would help so much!!!!!