Guy advice

So there is this guy that I like, a lot. I stay up late thinking about him, and when I get ready in the morning I tend to dress nicer than I would normally to "impress" him. (But anytime he's started a conversation with me is when I look really bad, a big old t-shirt, jeans, messy bun, and glasses) 
The main thing that I need advice on is that I'm scared to talk to him, because I'm scared of rejection. I'm scared that I will embarrass myself in front of him(because I always mix up my words, and stutter) and I need to know how to get over my fear of...him. Also, I've talked to my friends about him and they all say that it's weird I get so nervous around him, because I usually have this amazing confidence that no one else has. The times I have talked to him, it was amazing but I still don't understand what's going on, if I talk to him and everything goes good than why am I still so scared? Friends say I should just tell him that I like him so it's out of my system, and maybe for all I know he might like me back, but (like I've said over and over again) I'm scared to talk to him let alone tell him that I like him a lot. 
Any advice will help tons, and thanks for any help. Sorry for the long post.