Hi GBB,
Here's a bit of what I've learned, if helpful.
There are some things you can do which MAY help.
"May" because there's no way for people to compare their own results with what would've happened had they gone down a different path, and it may be that time is the best (and only) thing that works, when it works, and everything else is smoke and mirrors.
That said, if you have the budget...
First, there are a few things that are time sensitive, and supported by some research. I would do them immediately.
First is HBOT. Find a place that is able to provide sufficient pressure levels (noted in tinnitus studies), and arrange a series of sessions. You're on the tail end of what's been identified as a useful window, but I would still do it if I were you and ASAP.
Second is intratympanic steroid injections. ENTs often administer this in a series (say, 4).
Third is put together a team.
The forum is helpful up to a point, but no one here is your doctor treating you. "Team" because there is more than one discipline that might be helpful - an ENT you might initially see might specialize in handling acute trauma, whereas a neurotologist specializing in long term treatment will have different expertise. An audiologist specializing in tinnitus would be able to help in different ways still, including, for example, in the use of hearing aids tweaked to relieve tinnitus.
Frankly, from what you've said, it doesn't sound like you've been to any doctor who specializes in tinnitus, and they've all been dismissive. That's a common complaint. However, there are tinnitus specialists out there who won't be dismissive, you just have to find them.
Even though there's no guarantee all the kings horses and all the kings men can put Humpty back together again, they might be able to at least make Humpty feel a little bit better.
Therefore, if I were you, I'd research the field and find the experts in your neck of the woods. I've found that identifying one expert leads to additional experts, and with some work you can find the "good ones." If you have no clue where to start, I'd take a look at major medical universities and teaching hospitals near where you live, or talk to an ENT about a referral to someone they would consider an expert.
Finally, I'd be wary of snake oil and those who pedal it.
Good luck!