Caroline.... Have no fear..the dental expert is here! I can tell you that from five years of working in a dental office your problem is VERY common! I even experience it myself...even more now that I am a Nursing Student! First of all, yes, it is from stress. I find myself clenching my teeth at night AND during the day. I had been clenching for so long and not knowing it...it wasn't until I realized that much of my enamel had worn away and was beginning to experience severe sensitivity from the dentin showing through. I had to do something. Being that I worked in a dental office it was easy for me to obtain a nighttime 'mouth guard' to sleep with to control my problem. I recommend having a professional one made by your dentist...it is custom made to fit your teeth, very durable, very strong and will do the trick. It isn't however, a cure-all for your stress. If you aren't stressed you may not clench but when you are you will clench like HECK! :-) Get used to wearing it EVERY night so that no further problems arise. It does take some getting used to...your mouth may water when it is in and you may even discover a new found gag reflex...wearing it consistanly will rid all of those problem's. But start now...don't wait until you get like me! Youch! It hurts! Oh, and for that sore jaw...anti-inflammatories on a daily basis until it subsides (in correlation with the mouthguard!!) Muscle relaxers may be used depending on the severity of pain and frequent clenching...do talk it over with your dentist. Good luck to you.....Please email me with any other questions, I would be happy to help....we're in it together!!!! Good luck in school too! JenRn2B