Dude...move on. Unless she is saying she is going for secondary virginity then you need to move on. She loves you but she isn't in LOVE with you. You are giving her all the attention and respect of someone who respects you and she doesn't. I hate to say it -- but have you considered that she is seeing someone else and sleeping with them (thus not needing you for sex). There are guys out there who are sweet and awesome that never get sex; however the girl recognizes how awesome he is and wants to keep him around. Try pulling way back from her -- but you can't be outwardly about it...like don't tell her. Start breaking dates (the way she does to you). Stop responding to her texts / emails as quickly. If she believes you are her lap dog - she will treat you that way.
Ultimately spend more time working on you -- working out (not giving blood for dates -- jeese). Go do other things and lo and behold you'll probably find you don't need her as much and you may even find a girl who will sleep with you and give you crazy awesome sex. You are in colege man -- girls are in an experimental phase and so are you - there should be no reason to go through the hell of her games...sorry I had to be very direct here.