Dear Kevin,
I am so sorry to hear you are suffering so terribly right now, but I really encourage you to realize that even if this does not go away in the way you hope you can absolutely still feel good again.
Though no one can make you any promises (which I know is frustrating and scary) I tend to agree with Karen that tinnitus will calm somewhat over time provided you protect your hearing and take care of your body and mind in general. That said, I think part of that lessening of the sound is it actually being a little lessened, but mostly I think it is the person adjusting to the sound itself and their brain learning to "push it to the background."
I have no doubt that you tinnitus is as loud as you describe (hearing it over the shower etc.), but I might put forward that some of this is caused by you keeping tabs on it. Since you are in such a state of panic right now, your brain literally cannot ignore the sound. It's looking out for that sound in every situation because you panic is telling your brain that the sound is life-threatening. When I first got my own tinnitus, I could hear it absolutely everywhere, in places where I would now say I "can't" hear it - it's not that I can't, it's that I don't. Even in a silent room I often don't notice it because it's just turned into something no more important than the city traffic outside my window. I can hear it, but I don't.
In your first post here you wrote "Last Friday, after constantly checking my ears and trying to adapt." The thing is, you can't really do both of those at once. I know how you feel, because I was terrified, suicidal, panicked, couldn't see how I would ever live again and my sound was unbearable to me at the time my T started. It seemed like the end and I was constantly checking my tinnitus to see if it was going away or getting quieter, but checking it is only going to make you focus on it more and make your brain focus on it more. You checking it is actually doing you more harm than good - resist the urge! If it does get quieter, it will not be because you were watching it. Maybe instead of checking it, every time you get the urge take that as a cue to go do something else - play brain games (like lumosity)/video games...something that needs your full attention to complete. You might be amazed that the sound, even if just for a millisecond, can take second place to another activity.
Of course, I dearly hope your tinnitus goes back to something closer to what it used to be, but I feel like you should know that even if it doesn't, you can still have a good life again. I am so confident of that and you are in the right place for support while you navigate this difficult time.
One more thing you might want to think about - I see from reading above that you were on Klonopin for a while. I am definitely not qualified to offer any kind of medical advice, but from my own experience with panic and anxiety (when my T was new), talking to your doctor about ways to curb the anxiety might be one of the best things you can do for yourself right now. Get some good sleep and know that one way or another it can definitely get better.
We're here for you! Also, sorry for another tinnitus support essay from me - I just know you can be better and have felt terrified too, so I hope this gives you just a tiny bit of hope.