My old tinnitus faded over time. Not sure how long it took cause i was so habituated. But the piercing EEEE wasnt there years later when i did tune in to it, just a quiet hiss.
For my first onset it got worse at 6 months in, and then.. it got better. Took 1 year to have a decent level and maybe 2 years to have just a 0,5/10 ringing sometime even silence.