It may be a sinus infection or an allergy. The fact that it happens only in the AM is more likely an allergy. You could also have too much dust/allergens where you sleep. Does the problem happen if you change where you sleep either in another room or completey at another place?

See your doctor for prescription strength medication if in deed it’s an allergy. You could also try using OTC (over the counter meds) to see if they help. Good Luck. More info is needed to pin point root cause. Your doctor can run some test to see what is the real cause of the problem.