Nine hours later, I rolled out of bed, still feeling ill. I chugged some water and, even though I didn't want to upset my stomach further, I made some coffee. I figured that if my nausea was indeed caused by caffeine withdrawal, the only remedy was caffeine. A mug of coffee and a big bowl of oatmeal later and I'm doing okay. Not great, but okay.
I'm going to take it easy for the rest of the day. Maybe I'll do some shopping and hunker down at a cafe to get some work done.