I've had it for years and it felt pretty severe in the beginning, however . . .
Your brain will eventually learn to accommodate it . . . and it may not take long, perhaps as short as a couple of weeks.
As we age, the sensitive hairs inside the inner ear - within the cochlear - break or die off. These fine hairs are what captures sound waves. The process can be accelerated by an assault to your ears by loud noises,
like going to a Ramones concert back in the day or running very noisy machinery or being assigned to an armored fighting vehicle in the military.
In my case years ago, I was running a 10 HP shredder/chipper for days on end without ear protection. I was simply ignorant. Once I acquired tinnitus, it was then that I noticed for the first time that people who worked outdoors with loud equipment were using ear protection.
Thanks to this thread, I am experiencing tinnitus right now. A half hour from now when I am no longer thinking about this thread, it'll still be there, but I won't be aware of it unless something causes me to think about it.
It does appear to be more troublesome when we are fatigued. Some say that there are things that make it worse, like lots of caffeine. As bad as it has been at times, it was not as bad as going without coffee!
A couple of years ago, I got a couple of floaters in my left eye. One of them I refer to as "my fruit fly." As in the case with tinnitus, the brain is resilient and though the floaters bothered me for a couple weeks, my brain learned to see around them and essentially ignore them under most lighting conditions.
The best thing to do is read up on it and allow some time to pass. There will be a spontaneous improvement.
https://www.mayoclinic.org/diseases-conditions/tinnitus/symptoms-causes/syc-20350156
https://www.ata.org/managing-your-tinnitus/patient-stories/message-william-shatner-you
Edit: Once you have developed tinnitus, one of the things you want to do is protect your ears from here on out and avoid loud noises as much as possible.
I use ear protection now whenever I run heavy or loud equipment. You can't cure it, but you can make it worse.
Whenever a car goes by with a young kid listening to music so loud that it rattles the windows in my Tahoe, I want to jump out, shake the guy by the neck and tell him how sorry he'll be if he keeps it up. I don't do it because I don't want to be shot . . . and besides . . .
. . . does anyone think a young kid with a 500 watt stereo in his Nissan is going to listen to me anyway?