Nicky and Mel....
I have also started taking melatonin at night before going to bed. I read in an article that it is a natural form of headache relief. Seems to be helping a little so far! My night-guard is also made by my dentist and it fits over my two front teeth and kind of clicks in....so that I don't spit it out in the middle of the night. (Which is what I did with my previous one) I am on my 2nd one in a year...you are not supposed to be able to stretch them out...(it is made of some kind of hard material that the dentist shapes to your teeth), but somehow I ground so much that I loosened it up so that it wouldn't stay in anymore.
I know you were concerned about the cost of one from a dentist...I think mine was around $150...but I've seen advertisements for others that are better than the plain plastic mouthpieces. I'll try to find out what it is and let you know....maybe that would help also!
Shelley