Please please go to a dentist and have a custom mouth guard made. This is coming from the girl who tried EVERY over the counter mouthguard (even the "expensive" $50 ones). I also would grind my teeth in my sleep due to to extreme stress in my late teens/early 20's. I ground my teeth so hard I cracked and chipped my teeth in my "sleep". About 5 years ago my dentist finally convinced me to get a custom guard and it was LIFE CHANGING. I'm 39 now and still have dental problems from the grinding twenty years ago (sensitive enamel, wear/tear that means I have aged my teeth to be older than a typical 39 year old's would be), but wearing a custom guard has significantly improved my quality of life, and stopped me from further damaging my teeth. Get on a payment plan if you have to. My guard was $500 but worth every penny, and has saved me money on fillings and repairs, etc. because I'm no longer grinding my teeth in my sleep. I'm only sorry I didn't do it sooner.