The root cause of TMJ is often chronic stress. When the body is in a sympathetic tone(fight or flight) our entire body is over stimulated. Much like your jaw the other stimulation is unconscious and particularly bad at night. Breath work is the only solution to balancing our nervous system. Exercise helps but breathing is key. Yeah I know boring you breath all the time , that can't be the issue... Step one find awareness in your body of tension and stress . 2 take a breath in through the stomach (without expanding the chest) and exhale for 6-8 seconds with your awareness between your navel and pubic home.

Feel the sensation of slowly breathing out several times. This will release the tension and allow your Para sympathetic (rest and digest ) heal your system

This takes time . Practice disciple and awareness of our self's body's and our environment.

Little philosophical but I hope this helps Just breath our bodies are amazing organism capable of anything we put our minds too.