Is it normal to be unable to act naturally around hot guys?

Yes I feel the same. Because you are nervous. I take them to the woods where no one can hear their screams.

Normal people flirting : "you have really nice eyes, what's your name?"
Me flirting: " so do you like bread"

Right, I feel like such a loser talking to attractive guys.

I used to be like this around hot girls and my solution is a little vulgar but bear with me.
I just think of them taking a shit, I mean they piss and shit like everyone else. damn, even some of their farts they've done over time would've had to have stunk. They've had BO before, they've had bad breath at times, they've vomited they've bled they've had scabs and when they were young they probably picked their nose.
In thinking of the grotesque facets of human excrement, it brings my head down from out of the clouds and I can just see them as another person instead of some angel from heaven.

I felt that way until I worked at a gym for a while! You run across some very attractive guys there, and working there has made me much better at keeping my cool and striking up a casual conversation with them. They are just normal people :P so I guess, practice?