I was diagnosed a few years ago. As has been pointed out, there really isn't a cure for it, so it really is a mental thing to try and block it out/ignore it.
I've found now that the only times I really notice it, is when I'm in a virtually silent environment, or when I'm actually talking to somebody about it, as it then becomes a focal point.
It came from years of having a drummer down my right ear, but I don't play in a loud environment any more.
I did struggle to sleep because of it initially, but I have a radio on quiet all night now, and it very rarely causes me any problems. The worst was trying to have an hour's kip on a motorway services on a long overnight drive. Pulled into a dark corner of the car park, settled down, but the silence just exacerbated the tinnitus. Had no sleep whatsoever. Since then, I just find it easier to have a driving partner, and sleep while they drive.