Hi are you on oxygen at night? If so, there should be a plastic cup (humidifier) that you can attach to your oxygen machine to provide you with extra moisture.
With or without oxygen, you can get a daily moisturizing spray.
With oxygen: You can use a moisturizing spray. Do not use a petroleum product with oxygen. This spray, is good.
There is a sinus rinse that my allergist believed in. She wanted me to do it 6 or 7 times a day. Talking to my doctor and my pulmonologist, they agreed (independently) that I should do 2x a day, more if my sinus were stuffy. Allergies are tough. Then I use more as needed. That really helps to clean out the gunk and bacteria. It moisturizes too. Be sure to use distilled water only.
Janet, COPD.team