Constant Diarrhea TMI

I’ve had diarrhea all morning and it’s all because I had ONE cup of coffee after going a week without it because my insomnia’s been acting up. I’ve gone through one sleeve of saltines and two cans of Diet Sprite and I’m still running to the bathroom. What can I do?

TMI: The stool is greenish-yellow and sinks to the bottom of the bowl.