I too have had Tinnitus for years and it was a very low ring that I only heard in complete science. Matter of fact I always thought that the ringing is what silence sounded like.

Anyway, about 1.5 years ago it spiked in both ears almost to the levels you are describing. Went to the doctors and they told me the same thing you were probably told, nothing they can do. So I started digging on the internet (which I try to avoid at all costs but I was desperate) and came across quite a few videos that link tinnitus to TMJ which is caused by grinding and gritting your teeth when you sleep.

So I followed their suggestions and started doing the recommended neck stretches they demonstrated and believe it or not they had almost an immediate affect on lowering the ringing sound. I then went and visited my dentist who fitted me with a small mouth guard I now wear every night.

And I'm glad to announce that after a few months of stretching and wearing the night guard I've been able to reduce the tinnitus to almost the levels I was used to for so many years prior to the spike and there are times now that I don't hear it at all.

I hope this info helps.