Welcome, and congratulations on a clear scan!
It's a puzzlement why many ailments, illnesses are worse overnight. One reason for can be from the lack of mucin to protect the mucus lining due to the saliva glands basically shutting down when sleeping, which causes dry mouth, and irritation. It is worsened in those that sleep with the mouth open, certain medications, GERD (acid reflux), and chemoradiation treatment. Radiation can take up to recover, and sometimes not completely like dry mouth. There are different things you can try help relieve the dry mouth, and acid reflux.
Sleep with a humidifier.
Sleep on an incline to prevent help prevent GERD, relieves neck/head pressure too.
Brush, floss, rinse before bed. I use no alc biotene which enzymes help saliva
Drink water before going to bed
I apply biotene dry mouth gel before bed
Keep a bottle of water at the nightstand for easy access if awakened
There are tape products to help keep the mouth closed when sleeping
Take meds, with food, if allowed, same with vitamins and not at night
I hope this helps.