Sick...again

In the past 20 years I could count on 1 hand the number of times I've gotten more than a cough and runny nose. I was just sick 2 weeks ago and felt fully normal for the past 5-6 days. At 12:30 or 1 I went for a walk. It was too slushy to run and my knee is still a bit swollen. At about 2 pm today I started feeling really crummy. Stuffed up, runny nose, headache. About 3pm my stomach and head hurt and I was feeling exhausted. At 5pm my. Head was hot and my body was freezing. I took some cold medicine and I feel a little better. I'm doing my requirements super slow tonight to keep my head from exploding.