I surround myself with noise.
A fan (in the bedroom at night and in the den), music in my office and in my car, etc. Yeah I still hear the ringing quite loudly, but the "aids" I listed help keep my mind off it. I've tried some sort of ear plugs designed to calm down the ringing (due to some vitamins, etc in the wax), but they didn't work either.
Maybe an allergist or ear nose and throat doctor could suggest a remedy. My last one didn't have a solution, but just because he doesn't know doesn't mean another doctor will give the same answer. They all go to school at different places, and read different materials each day.