Re: New to all this/ still waiting to see a specialist.
if you do in fact grind your teeth that intensely, that might have triggered the TMJD. Especially if you grind/chew more on one side (many people do), that leads to uneven teeth length forcing your mandible to compensate by overclosing on the shorter side and thus, uneven bite. This all causes pathological muscle reaction that leads to teeth movements and pains allover the body.
I think you did good by using the nightguard; however, your bite is already uneven and the nightguard alone would not be able to stop it (although it certainly slowed things down). I think you might greatly benefit from using the TMJ bite splint.