Do you ever feel uncomfortable around someone you think is hot?

I don't mean to sound braggy, but I'm an attractive woman and it's not difficult for me to attract good-looking guys. The problem is, whenever I'm totally attracted to a guy that I think is REALLY good-looking, I get so nervous around him and I feel so uncomfortable! Why??!! I'm a college educated person, yet I feel like I sound stupid when I talk, and if the guy is looking at me when he's talking, I can't stop thinking about what he might be thinking about me! Crazy, I know. How can I stop being like this, and why am I unable to just be cool and calm. Sorry if this sounds bad but when I talk to ugly guys I have no problem and I usually take charge of the conversation and I don't sound stupid. I don't want to be like this! What can I do?