Just to share my experience. I think I was beginning to develop sleep apnea: I was waking up suddenly with an awful feeling of something terrible happening for no reason. The most terrible experience was waking up in the middle of the night with a sensation of dread I couldn't explain, and it took me half an hour to calm down.

More generally, since I was young, I always slept part of the night with my mouth open and woke up in the morning with a terribly dry mouth.

Now I have solved my problem with two simple things, without any medication: during the day, I am always careful to breathe only through my nose (except during intense physical effort), and at night, I just use mouth tape to keep my mouth closed all night long.

Since I started using the tape on my mouth, I sleep well and I no longer experience nighttime panic (due to apnea?). At the beginning, I was scared of having the tape keep my mouth closed, but I very quickly got used to it and now I barely notice it.