Is it normal to pain over talking to a woman?

I have become single again after a very long relationship. After some time I have become interested in getting to know someone on a dating type level. It is the case that I am an unusually/better than average looking male (i know because its just true, am told by many I am the rugged hotguy type. Plus I own mirrors lol). But, I have painfully difficult shyness issues. Painfully shy for a lot of crap I went through at a very young age. But, I warm up after a while and am myself after I know someone.
I am not interested in many women I meet on a level past casual like. But there is this girl who captures my attention. A clerk at a gas station on my way to work. Sometimes I stop, just to see her and pretend to be there to buy stuff. And she sends me all the right signals! But I am paralyzed. I do not know how to take it to the "i like you" level without becoming sickeningly afraid. Its pathetic. How do you let a girl know you want to get to know her when she is a stranger? How long should I wait?