My head is throbbing...

I got a fever while at work... I was told to 'Go home. Go to the hospital' because I might infect the residents, so I left early... Friday afternoon, a slight fever of 37.4°C and a terrible headache The waiting room was crowded The doctor said, 'It's a cold. However, it's a bit of a tricky type of cold, so please monitor it for 2-3 days (because you might infect the residents).' I contacted my workplace. On the phone, I could clearly hear my manager sighing, clearly displeased... I'm sorry, it was my fault for not managing my health properly. I've been staying at my grandparents' house for the past month to take care of my grandfather. Since I didn't want to infect him or my grandmother, I returned to my own home for the first time in a while... I don't have a cough or runny nose, but the fatigue and headache are severe. My shoulders and neck are stiff. How did this happen...