What's the dB level of white noise measured on your phone that you need to mask this so you don't hear it in a room? If less than 25-30, you're in the mild category and this might clear up on it's own over the year.
I know you don't think so, but you really can get used to it and things will turn around over the next few months, even if it doesn't go away. I talk regularly to a guy that got noise damage and his did, in fact, go completely away over a year. It went from always there to not.
Lots of people swear by NAC, Ginkgo biloba and Magnesium (not oxide) to help. Could always try those out. There's some evidence those actually help. It's probably better even if it does nothing so you think you're doing something
Do you have hearing loss in the left ear?
If you did you should aggressively pursue more diagnostics (more than 10 dB difference than the right ear or your last test).
A good old blood screening for the typical (TSH, vitamins, minerals, CBC etc) is also a good idea. For all you know this is an easy fix.
For now? Good old pink noise if you can't hear it while that's quietly on. You will be ok even if it decides to be your freeloading roommate for a while. But, consider this a stern warning (it can become an actual monster). Headphones as you will shortly hear from people is also a terrible idea unless you have a acoustic neuroma (see "hearing loss above", treatable too, but way more serious). Also watch out for ototoxic drugs.
The "original" rings of noise induced trauma I got... from very intense sound... have mostly become inaudible except in a library over a year. I don't really know why, I just have theories. The answer remains. Time & vigilance over "damaging" sounds +70 dB. It originally blared like a siren as if I were in front of a honking car that never stopped. Mine worsened from unforeseen other variables and risks I took in sound and treatments. Given you are younger, whatever caused it you'll likely bounce back from too. I wouldn't recommend any medications either unless you woke up deaf in that ear.
If it keeps getting louder, is really low pitched (so not ringing or static) or you lose hearing, get an ENT to take you seriously, and get a hearing test. They won't lift a finger for you until that's done.