Re: about night guard
I would recommend going to a dentist that specializes in TMJ, such as a neuromuscular dentist or oral surgeon. The type of splint you receive is a case by case basis, taking into consideration what condition your jaw and teeth are in. This is by far the best option in my opinion if you are able to do it.
If one custom made for you is not an option due to insurance or finances, an over the counter splint that can be helpful (helped me a little many years ago) are the sleep right ones. They can now be found at Target, but a greater assortment are available online. I had to use the one for sensitive/petite mouths due to the condition of my jaw. It was a temporary solution until I had the insurance available to get one custom made. Be aware however, if you are a clencher/grinder like me, the sensitive mouth one can be fairly easy to chew through. From what i've heard it is not seen often, but I did it ever month-3 months depending. Hope that helps!