I am fairly new here but the audiologist I have spoken to (if I remember correctly) said that there are debates whether tinnitus comes from the ear or from the nerves in your brain itself. She told me about one case study where the subject had severe, disabling tinnitus and went as far as cutting the cochlear nerve (or something like that) to make them self completely deaf in hopes of curing the T but still has the T as his stemmed from his brain, not his ear. again, I'm totally new here so others may have better info!
As far as TMJ, I also suffer from TMJ and it can be treated. Make sure you find a reputable TMJ specialist and get yourself a night gaurd / splint to wear that will correct your bite and hopefully realign your jaw. I've been seeing a specalist for a year and he's made a HUGE difference in the quality of my life. I recommend you get your TMJtreated if you haven't yet.