Dude...I know that feeling...Sucks don't it?!
I heard a great philosophy on life a few years ago...changed my life.
"A cautious man will live safely...But only an adventurous man will truly live!"
Take the chance...Tell her how you feel.
If she shoots you down, get back up and go find another broad to take the pain away!
Seeing as you're leaving sooner or later, what does it matter if you get a negative answer from a girl?!
There's my advice...Take it or leave it!
Good luck man!