Some years ago I had a Tinnitus as well. It was a very low frequency around 100 Hz, so pretty rare I think. I went do the doctor and did get lots of examinations und cortisone. I even had an electrician at home to change the fuse box as the old one made some noise in the same frequency range. Nothing helped. In the end the Tinnitus went away and I have no clue why. What I'm trying to say is: there's hope. Good luck!
Edit: I even went to a dentist and an orthopedist because it's possible, that the Tinnitus is caused by teeth or the spine.