I have a constant cough that hurts the back of my throat if i cough too hard, on and off body chills/shivers/aches, on and off headaches, and slight fatigue, and also took a covid test and came back negative multiple times. what could i have?

There are a number of respiratory viruses and Strep infections that may cause your symptoms including Influenza. Monitor temperature and breathing, drink fluids, rest and if the cough doesn't improve please see your physician. Watch for signs of shortness of breath and fever. An over the counter cough preparation with honey is often effective in reducing the cough.