I wear a night guard for other reasons. I do not know if they are available over the counter.

Not unless you are considering a mouthguard like young athletes do. You need your dentist to take molds of your teeth and send them off to create the mouth guard that locks in place on your teeth. Unlike the sports mouthguard, this two piece mouth guard is not connected, and not only does it prevent you from biting your tongue but also grinding your teeth.

You’re having seizures during your sleep, making you bite your tongue. I have bites mark all over my tongue

Janet,
I mentioned my chewing on my cheeks so they bleed. She said I had Bruxism (grinding teeth), so the mouthguard was needed. When I was with Dorothy, she kept track of all my seizures, even those at night. Not sleeping well or enough, not eating enough or well are both Triggers, being overheated and stress are others.

I can guarantee that you are seizuring in your sleep. I use to do that a lot myself when I was younger. I still have Thousands of welts on my tongue, from biting it during my sleep seizures.