Anon, I'm wondering if your jaw is mis-aligned, and on one side it's pushing against your ear. That is known to cause tinnitus, although I'm not saying it's the only possible cause.
I am not a doctor myself, but my own jaw is horribly out of line, thanks to my fucking orthodontist when I was a teenager. Decades later, after my health was wrecked, a jaw specialist saw my dental xrays and almost wept. He could see how fucked up my jaw is, and he understood all the myriad of health problems it causes. Headaches/migraines, sinus and ear problems, posture problems, leg/knee/shoulder/neck problems etc. etc.
Anyway, that's how I know that tinnitus is sometimes caused by this. Best wishes