Here's the thing. Pick up a decibel meter like this. Then, put it in a listening position where you head would be near some speakers. For example, rest it on top of an office chair in front of a computer with speakers. Play some music, and get it to about 70-75 dBA.
Remove the meter, and sit in that chair. Listen to the music, then put your earbuds in and try to approximately match the volume. What you'll likely find is that the volume is pretty low, and what you're used to with earbuds is much, much louder.
You can do the reverse: play audio through your earbuds at about the volume you typically listen to, then play the same thing on your speakers. Turn it up until it is about the volume of your earbuds. Then, stand up, put the meter on the chair, and measure it.
If you don't want to go through all this trouble, roughly speaking, you don't want to have your music any louder than a lawn mower. Higher volumes take less time to start to damage hearing. At higher volumes, exposure for any period of time can cause permanent hearing loss.
So yeah, absolutely do not make any assumptions in sound. Hearing loss is cumulative, and in today's age, still permanent. It also can cause significant psychological issues like depression and anxiety. You don't want to destroy your ears on purpose at any point in your life. Protect your hearing starting today.
I've been reading this book by Norman Doidge and in it they speak to low level laser therapy (LLLT) being used on some people with hearing loss/tinnitus and the positive effect it had. The man behind the LLLT in the book is Fred Kahn but where I see differences between the LLLT he offered and most others is the laser for one and the duration for another. I would also look at this meta analysis. Like many things, I think it has to do with the type of tinnitus. I think it's worth investigating which types of tinnitus it has helped and going from there. Let us know how it goes as I'm curious about it as well.
I thought these neuromodulation devices cost thousands and have efficacy levels similar to my tinnitus sound therapy app (roughly 85%). My app is the price of a beer, so I'll pass thanks :) https://play.google.com/store/apps/details?id=air.spikything.tinnitustherapy.pro
1) To get short-term relief, ask your doctor for mirtazapine/Remeron. It's an antidepressant with relatively few side-effects that will help you sleep (immediately). The first week you'll be in a bit of a haze, so if you are working, consider taking a week off. After the first week, the haze should go away. Getting good sleep will not make your tinnitus go away, but will lower its volume a bit. In addition, after 2 to 4 weeks you will feel the anti-depressant effect, so your mood will go up. Again, it will not make your tinnitus go away, but it will make it easier to live with it.
2) For long-term relief, buy the book 'Rewiring tinnitus'. There are good exercises in the book that will help you to cope with tinnitus, but it will take time and patience (that's why you should think about taking an antidepressant; you seem pretty distressed). Alternatively or additionally, try to get therapy. There are specialists that offer specialized tinnitus coping therapies. It's sometimes not easy to find the right therapist and sometimes it's not covered by your insurance, but it's worth a try.
Which brand do you use? It seems to spike me when I take it but maybe I'm similar and another form would help. I use this currently (does not help):