Why is talking to guys so difficult?

"Hey, whats up?"
"Aaaa, nnotthhing."
That is an example of me talking to guys like everyday. For some reason I can't even say one sentence with out feeling embarrass for stuttering my words or switching letters in some words. I get so scared and weird when I talk to boys. Is it hormones or just stage fright? I think it is a little bit of both. In very many situations I see myself frightened to talk to a guy I like. It is so annoying; I guess thats how life is. Everyone has their ruff spots here and there, but we or I must never fall to the state of being afraid of men. It will only leave you to self-pity, so never give up on taking to guys no matter how weird you sound or speak.