I have an upset stomach but I need caffeine. What should I do?

I have an upset stomach, not sure why. I have diarrhea and I threw up this morning. I ate some breakfast, but it made it worse, and I generally feel like hell. Thing is, I’m a college student with final papers to complete and I need to work today. I’m super out of it and tired and having caffeine withdrawal. I know that caffeine can worsen an upset stomach, but I also really need to work. What do I do?