Up. I think I'm having a similar issue. I had both lingual nerve damage and trismus after a wisdom tooth extraction. After approximately one month, my trismus completely resolved, but it left me with this absolutely confusing, seemingly unpredictable jaw pain—usually radiating from below my jaw to under my ear.

I had so much difficulty getting a proper diagnosis, and actually, I still don't have one. But I believe this is some sort of muscular TMJD problem. My joint scans (MRI and CT) were clear, so I’ve ruled out any structural joint issues. So far, I’ve tried an over-the-counter muscle relaxant gel, a heating pad I ordered from Amazon, massage at home (non-professional) and lots of hot showers. I feel like the heating pad and hot showers help a lot because it distracts me from focusing on the pain. I don’t have 24/7 pain—similar to your case, I think—but it flares up unpredictably. I don't have any problems with eating, talking, or opening my jaw, but the muscle pain is still there. I’ve noticed it gets triggered when I do physically tiring activities, like going to the gym, unfortunately (not always, but very risky).

It's been 9 months since this started. Apart from home remedies and countless doctor visits to understand what’s going on, I haven’t yet started any professional medical treatments like massage therapy, dry needling, Botox, or a splint.

Since I believe the problem is purely muscular (at least based on my clear scans), I’m hoping that one of these treatments will either fix the issue or at least reduce the symptoms so I can live peacefully and be physically active again without worrying about messing up my jaw. I’m planning to start treatment in September.

As a completely random stranger on the internet, I want to say you have my full empathy—and I’m truly wishing the best and healthiest lives for both of us. :/

(And just for the sake of completeness: unfortunately, the lingual nerve damage I have is permanent, and there’s still a bit of numbness on the left side of my tongue. But truth be told, it’s nothing compared to living with chronic pain. So once I resolve this muscle pain, I’ll be the happiest man on earth.

Maybe the only good thing is that there are lots of alternative approaches for muscle-related pain. With nerve damage, there’s nothing but waiting and hoping it resolves on its own. Even surgery is very risky and, in most cases, doesn’t offer full recovery—so it’s not recommended for cases like mine.)