<human>: I've been having headaches off and on for the past 2 years and I have a few ideas about what's causing them, but the behavior of them is so bizarre. 

When I get a bad one, like today, I get a sudden onset of nausea that leads to vomiting and possibly a slight fever (never taken my temperature). Almost instantly after I vomit my headache eases into an uncomfortable rawness, but very manageable. 30 minutes after I eat much of anything the headache comes back in full force and I vomit again. 

Here's where it gets weird. If I don't eat anything, my head will not hurt anymore. I'm seized with a ravenous hunger and want desperately to eat like a double cheeseburger or something, but if I can hold off and not eat anything I'm fine to not eat for hours and hours, essentially the rest of the day. 

So today my head started hurting around 3:00 PM and I vomited around 4:30 PM. Its currently almost 10:00 PM here and I haven't eaten anything other than a few raisins since. I'm hungry, but I feel like I could realistically go for days without eating.

Can you succinctly summarize the text in 1-3 sentences?
<bot>: I get headaches that cause me to vomit. Vomiting makes the headache go away. Food causes them to come back.