I think I may be in love with my instructor......what should I do?

You don't have to do anything. It's just a thought. Let it pass in your mind like a cloud passes through the sky. You can't control your thoughts, but you can control what you do about them. For example, someone may be very angry and contemplate killing someone else, but that doesn't mean they actually have to go out and do it. It's okay to admire someone else, but you obviously need to leave it at that, since she's your instructor, she is straight and she is married. In fact if you do try to approach with intimacy, I think you may be worst off than you are now.