Did you think it was Covid based off the symptoms or was it a positive test when you started feeling sick? Lots of water and plenty of rest should get you back on your feet as soon as possible, but definitely take your time getting yourself better. Glad you're testing negative!
If it was flu tamiflu is only effective within the first 24 hours of symptom onset. Fever is therapeutic as long as it's not too high so don't treat if less than 101 oral temp or 102 temporal. This makes you feel bad but get better quicker. Likewise, take an expectorant with your fluids but don't take cough suppressants during the day. You want to clear out the junk so you can sleep easier at night. Use a humidifier and Vicks on your chest at night. Get a little sun on days like today.
I had something a couple of weeks ago with the chest congestion and cough and everything and I tested negative for all the things. Covid, flu, strep etc all negative. He just called it a sinus infection and gave me antibiotics. Symptoms lasted for like 10-12 days. Super annoying!