Ok, is it a soft night guard by any chance? If so, throw it away. They make it worse.
I’d start out with a chiropractic adjustment. Preferably a chiro who deals with a lot of TMJ. Sometimes an adjustment and a chair massage will sort you out within 24 hrs. If not its 50 units of botox (25 in each) into your masseters. If the TMJ is coming from your clenching, this will be life changing. I do this on patients all the time and have done it on several bitcoiners at conferences. It’s a game changer.
If that doesn’t alleviate it at all within a week, you need to see an ENT to rule out Meniere’s Disease.
If you are better, but not 100%, you will need a lower flat plane splint night guard adjusted to your occlusion. A well adjusted one should make your joint and face feel at rest when it’s in.
Hope that helps.