The brain is trained and I guess we are driven by the concept of neuroplasticity. The brain takes an input, decides what to do with it and can produce outputs. In tinnitus the cause is believed to be the damage or loss of certain fine hair structures in the inner ear (loud noises can cause that) which produce a constant faulty signal to the brain, but the brain could also potentially be intrepreting a reasonable signal incorrectly and perceiving tinnitus, which is why it can be a tricky thing to diagnose. You should always have an MRI for the ear just incase there is an infection or something else seriously wrong, you need to rule that out.
Once you are at the stage wherre you have tinnitus and there is no physical issue obviously causing it then you are into the retraining of the brain part of treatment. The more you focus on the tinnitus the more you will train the brain to hear it and thus make it louder and worse. The more you can ignore it the quieter it will get and the more it will disappear. You need to get your brain off that noise for long periods of time. You need to distract it with other stimulus. You need to find a mechanism that relieves the focus on the tinnitus and use it to retrain the brain over the next few months. When the mechanism you found no longer works find another, you will have to keep switching as the brain gets "bored" like that and you have to constantly adjust the stimulus novelty to keep it focussed on something else. Try pink noise, white noise, try different genres of music, sounds of nature and waves etc. Anything that gets you hearing stuff that isn't the tinnitus and makes it less bad.
You can fix this, the signal might always be faulty, something is broke in your ear more than likely and you may never hear that individual grouping of frequencies again and you honestly wont want to as they may exacebate your symptoms. But what you can do is get that signal in your brain to the point where you don't care and it never bothers you. Our brain is plastic and can be completely retrained how to intrepret an input and that is something you can do. You can supercharge the idea if you have a look z health, they neural retraining exercises for a variety of sports injuries and such but they have a video up today about test/retest that may help you find good stimulus that is performance, neutral or rehabilitative. You can use that mechanism to test how much your brain felt the stimulus helped or hurt.
Good luck, I rid myself of mine (it is still there just quiet and I don't care) 10 years ago so I know you can do this.
