I need to talk to him, but I'm so nervous?

[Shania]

I've always like this guy. But it's kinda the high school crush thing where you still chase after boys. We've just stayed friends because I never gave a relationship a thought. We're seniors now, and we've gotten really close. In November, he told me he liked me, and I didn't even see it coming. I fell for him hard and I realized I really do have feelings for him. I catch him staring at me sometimes, we hang out almost every weekend, we've kissed, we've even slept in the same bed (JUST slept...), we've pretty much done it all and he's become one of my best friends. I feel like he's been stringing me along since then so he keeps me all to himself. It's killing me because I really like him. Everything I tell him I mean, but I don't know if he does. He acts like he does, but he wont say it out loud. I've told him more than once that I like him. He's always texting me saying he misses me, he's thinking about me, he's falling for me, etc. Back over the winter, he said he wasn't ready for a relationship. I've tried moving on but I'm stuck to him. I keep coming back to him and he sent me a message on Facebook the other day saying we should give a relationship a try soon. How long do I have to wait? He said he understands how frustrated I get with him, and I've put up a lot with his crap. He said he would talk to me more about it, but he hasn't. I just wanna be with him. I need to call him tonight to tell him, but I'm so afraid that if I say the wrong thing he'll leave and I'll never know what it was like to be together. The reason why I need to call him is because everything seems fine through technology...Facebook, texting, etc. but when we're together face-to-face, it's like nothing he said even matters. So I'm gonna call him but I'm so nervous! Any ideas on what to say or how to start it off? I just need to talk to him, I can't wait any longer...