This is kinda weird.. But try not to lay flat on your back. Sleeping on anything but your back will help. It allows more oxygen into your lungs. It's called proning. I tried it when I was sick and mine didn't progress despite already having asthma and being prone to pneumonia, here it is in more detail- the proning positions https://mountnittany.org/wellness-article/covid-lying-in-a-prone-position-proning#:~:text=When%20you%20have%20COVID%2D,help%20prevent%20lung%20injury.

If you don’t have one already, get an inhaler and use it when you have coughing fits !

Get the antiviral drug if you can.