Trust issues with girlfriend

For a while, my girlfriend has suffered from depression with it constantly getting worse, despite my effort to help. We have been dating for six months. Tonight she finally told me that she realized what her full problem was and why she was always depressed; jealousy. She always finds herself comparing her body and looks to previous girlfriends and crushes of mine. She said that the only way she can be happy is for me to stop being attracted to them and for her to think highly of herself. Here's my problem; I am not attracted towards those people. And I have told her numerous times that she is the only one I have my eyes on yet she doesn't believe me. I do everything in my power to make sure she knows I love her and everything about her yet she doesn't seem to realize. What am I supposed to do?

I don't mean to sound rude in this email I do however what to be honest if you are being a loyal and caring boyfriend and if you are not doing anything to make your girlfriend feel threatened by other women ie flirting secret texting etc then these issues are your girlfriends issues and you shouldn't feel punishment for anything you don't do. Your girlfriend must learn to trust you and to have confidence in herself. I can recommend a lady for her to speak with if you like she is brilliant