How To Treat Persistent Scratchy Singing Voice?

Im a 36yr old female that is having a problem with my voice. I have had a persistent scratchy singing voice. I love to sing and am a natural soprano. I will start to get my singing voice back and then the problem returns and causes my throat to become sore again. Another symptom (not sure if it is related) is slowed hair growth.I have had my thyroid checked and it checked out ok. This has been going on for about six months now.