There Is A Cut On My Girlfriend's Clitoris With Pus

There is a cut on my girlfriend's clitoris with pus discharge and she says it hurts her a lot. She can't get horny and she doesn't cum. She's had it for about 2 years now and refuses to see a doctor because she's embarrassed. She had it before I met her. Any ideas on how to cure it? and on what it may be? What type of infection?