The ultimate solution to this problem to find a passion that puts you in the position to not even need a woman in your life. This could include a business, hobby, or something that you're inspired by. This takes awhile though.
Let me give you a little example. I met a girl my first semester in college and totally fell head over heels for her. Now, I didn't have a job, nor any hard classes so all I really thought about was THAT GIRL. Eventually, I noticed I was being needy and snapped out of it.
I started my own promotions business up. Not only was I making bank, but I had something to do during the day. Believe it or not, I almost forgot about the girl! The girl of my dreams per say, I forgot about. She went absolutely crazy, and to my surpise, I was having no problem being myself around her.
Ok, so that's a longterm fix. The only quick fix for now is to keep reminding yourself that you DON'T want to come off as a wuss, and you want to come off as a man whos on top. If you lose your stance one bit, she may flake and go for someone with higher standards. If you keep this in mind, trust me you'll rarely let yourself fall for her. While your busy telling yourself this, FIND A PASSION!