No cure so you gotta rest. Nose is stuffed so you gotta mouth breathe. Throat is dry from mouth breathing. Dry throat makes it painful to swallow. Pain keeps you from sleeping and recovering. Lack of sleep leads to worse symptoms like piercing headaches. Need to rest to get rid of the headaches. Headache and swallowing is too painful to rest properly. Lack of rest perpetuates headaches, nose congestion, dry throat, painful swallowing.
What is this BS
Certainly possible, if not likely, that when these viruses first evolved to infect humans or human ancestors they caused increased mortality. Common coronaviruses and rhinoviruses still kill a lot of people, they’re often associated with pneumonia