Mouth breathing

Tips to stop mouth breathing

I recently got a mouth guard from my dentist for when I sleep because I grind/clench my teeth but every night I wake up with a dry throat and I asked my roommate to check if I was sleeping with my mouth open and sure enough I was. I never mouth breathed before I had the mouth guard is this something I should worry about? Also I think I might have got a sinus infection from mouth breathing because a few days after I started using the mouth guard I got sick and had phlegm in throat, stuffy nose, ETC and I rarely ever get sick it’s something that happens once a year (apologize for English if it does not make sense it is my second language and I am not as fluent I am with my primarily language)