I don't think your TMJ has anything to do with the other symptoms.

I am in agreement with your dentist who thinks you may just be grinding your teeth at night. More likely just clenching your jaw. I did this. SSRI's can cause jaw clenching.

My jaw actually locked and I could only open it 1 finger width for about 6 months. I looked into the various treatments that were expensive and uncomfortable. Finally, I told my physical therapist and she did some in mouth therapy and got it to unlock. She uses myofacial release techniques. A PT treatment from time to time allowed healing. Now, I can open my mouth 2 1/2 to 3 finger widths.

I have lots of clicking in my right TMJ and mild clicking in my left. People near my can hear it. It is no big deal. Once I stopped the night time and even some daytime jaw clenching, both sides improved. No mouth guard or anything but the PT and resolving the jaw clenching. The gabapentin I take nightly appears to help me stop the jaw clenching as it helps my muscles relax.

Jaw clinching and body rigidity issues are common to PCS and even worse if one is taking an SSRI. I added 4 inches to my chest because I was constantly holding my upper body rigid.

If you are a side sleeper, that can be rough on a TMJ, especially if you have a tendency to sleep with a hand under your cheek like many do.

There is a Botox treatment for jaw clinching. They shoot Botox into the muscle that closes the jaw so it is weaker and less prone to clinching. I was about to have it done when I found the PT treatment.

So, I suggest you focus on whether you jaw clinch and work at resolving that. Otherwise, you may experience a situation where the cure is worse than the ailment.