I tested positive for COVID last year and now for the past two weeks, I've been dealing with a cough and trouble breathing, though there's nothing else going on. I've been using an oximeter, and my SPo2 levels are hovering between 92 to 94. I've been doing steam inhalations and gargling regularly which has helped a bit over the last few days. However, the cough is still bothering me, especially at night when I'm trying to sleep. Sitting up feels a bit better, but as soon as I lie down, the coughing starts and I just can't sleep. What could be causing this and is there anything else I can try to reduce the coughing and get some rest?