There are many theories with regards to tinnitus, but I always seem to see it in patients who are anxious and who find it hard to relax. Look at yourself, see what you can change about the way you live, the way you feel and think about things. If you were a patient in my room I'd put you through some relaxation lessons which would be specific to the behavior/s you would be exhibiting in my room at the time.
As you put it, loads of stress, alcohol, mercury. Remove these stresses from your life. Stress KILLS people every day!