How do u get rid of hair casts without shavin your head?

I am a 30 year old female who has had this problem for over 4years now. Two doctors have confirmed that it is not lice and a dermatologist has prescribed an antifungal which has not helped. I have very long hair and do not in any way want to shave my head or cut it short like a male haircut-I have tried vinegar and it did reduce it but it comes back. I am too embarassed to go get my hair done. I do wear my hair up in a ponytail a lot and have tried to reduce it but I've been doing it for years. Please help!