Sorry to hear you're suffering.
Firstly if you haven't already done it get a check-up with the GP, usually there isn't a "sinister cause" but you should rule it out.
I was told, "we don't know what causes it, we don't know how to fix it, but it won't kill you and most people are able to ignore eventually."
They were right, but I did have quite a rough time initially, especially sleeping.
My advice to you, (apart from a check up) is you'll be amazed how your brain will work out that it needs to ignore it and you'll be able to enjoy life.
You may need some short term help with sleep, which I would speak to your GP if this is an issue for you.
Good luck and keep us posted!
P.S. The only time I hear my "T" is when I think about it, like now...but it will be gone in 5 minutes.