Headache after flu

Hello!
I had the flu this past week, my temperature hovered around 100 for 3 days, and I began to feel better yesterday. Last night I took a walk and then I got the worst headache. Tylenol did not help, aspirin did not help. My blood pressure has always run a little low, not sure if that would cause the pain. I've been drinking a lot of coconut water. My headache goes away for a short time after I eat, but the minute I start to get hungry again, the intense pain begins again. Anybody know what this might be and when it will go away?

Background: 45 yr old female, fairly healthy, on my last day of my second Humaworm cleanse.

Thank you!