You've all heard the advice "don't act desperate." Because obvious desperation is a total turnoff. Well, my advice is to avoid situations that MAKE you desperate. Sometimes desperation is understandable, like when a guy withholds affection, or surrounds himself with girls who are throwing themselves at him, and any sane girl would feel the urge to work harder than she should to win over the guy's affection. It can make any girl crazy. So avoid it!
It may seem counter-intuitive, of course. If you find yourself obsessing and willing to do whatever it takes to get someone to pay attention to you, the last thing you want to do is pull yourself away altogether. But any relationship or dating situation that's negatively affecting someone's mental state is not good. Love shouldn't hurt, love shouldn't make you doubt yourself or wreak havoc on your self esteem, or make you feel guilty all the time, so if you find yourself feeling that way, get out and find someone who doesn't screw up your well-being like that! You're better off alone and doing things to make yourself happy than driving yourself nuts making a relationship work.