This is something that almost everyone goes through I would imagine. I have dealt with it with varying degrees of success. Sometimes its easy, and sometimes, often inexplicably, its nearly impossible.
That being said, the general idea is to avoid thinking that this girl is "a big deal". Many of the basic DJ principles come into play: don't put her on a pedestal, be the prize, spin plates, etc.
Here are some ideas that may help you:
1. (Most important) Your main priority must always be your life, career, health, diet, etc. Have a passion (besides women) that you care deeply about and relentlessly pursue by setting short and long-term goals. This makes success with any individual woman not as important, and thus relaxes you in conversation as you are no longer as worried about what she says or how she reacts to you.
2. Spin plates. Approach and talk to women.
3. Realize that this girl has negative qualities. Everyone does. Look past her looks and sexual energy.
4. If you find yourself thinking about her and analyzing your interactions when she isn't around, stop and refocus your energy on something else.
5. Become outcome-independent. When you are with her, focus on having a good time yourself. Not on entertaining and pleasing her. Success=having a good time. Success does not equal getting in her pants. That's just a bonus. If it doesn't happen, you aren't as affected because of #1.
6. Don't start planning the wedding. An exaggeration, sure. But if things are going well, just enjoy the moment, hook up with her, and repeat. Let her worry about the relationship stuff.
7. Look at your interactions as her opportunity to prove herself to you. Not the other way around.
Its a great feeling to have a girl you are totally consumed with--at first. When it goes south (as it naturally will, no woman truly wants a man who is obsessed with her) that feeling with turn south in a hurry and you can easily become consumed with negative thoughts. The idea is to avoid both extremes.