So, according to an x-ray and an oral surgeon, the cartilage in my TMJ is still mostly fine, and my jaw issues are actually from the same severe, painful, involuntary muscle spasms I experience throughout much of my body.
With that understanding going forward, I can say what is helpful for me personally.
Magnesium has been really helpful. It'll mess up my gut if I take too much, but there are days where I'd rather have a bellyache if it means I can eat.
As far as Rx treatments, baclofen got me from a place where I had only eaten milkshakes for about two weeks to being able to eat solid food again. I respond well to gabapentinoids in general, and I could get major relief from as little as a threshold dose of 5mg. It's not something you want to take for an extended period, because it can have a withdrawal period like a milder pregabalin or gabapentin discontinuation. But it has been an absolute lifesaver for me when my jaw is really hurting or popping out of place when I try to eat.
I also find it helps me, personally, to apply moist heat like a shower or a compress, then gently press down and towards the chin along my jawline to push the little mini-pops of muscle and soft tissue just slightly out of its usual alignment. It's like a softer version of massaging a back and getting those little cracks as the tissues slide into their default factory positions. I find it'll help ease the tension that's keeping my muscles in spasm and making everything feel angry in my jaw.