To tell the truth I know plenty of people who have same simptoms as your gf, they are not easy to deal with but does not mean that they are sick. All of us are "strange" in one way or another.
I can be without any "sex" it came from my "soviet russian background" where word sex considered to be dirty and also the way I am.
I was experienced sexual abuse myself and were talking to "shrinks" found them not just useless but hurtful. They are happy to discuss shopping and weather on your expense. They can tell anybody that he/she has chemical imbalance and put on drugs, I don't believe that what you want.