Was the night guard one of those drug store pieces of crap? Because yeah, they don't work. Until my custom made one was made through my dentist, I used one of those. No support and they don't stay in well. Sadly, the dentist ones do run several hundred dollars. But at least they're designed to fit your mouth. I still wear mine every night, even though the acupuncture got rid of all of the TMJ pain because that didn't stop me clenching in my sleep.