I have a bad case of diarrhea ?

Ok,your question is?: First define the problem (do you have soft or frequent stool?), circumstances under which diarrhea developed (malabsorption, pancreatic maldigestion, food intolerances, stressful times, exposure to ill individuals, food poisoning, ischemic gut, inflammatory colitis, etc.), severity (stool volume, dehydration, blood, night-time awakening, weight loss), & duration. The "cure" depends on diagnosis.

See your doctor: or go to an urgent care for stool culture and treatment. In the mean time follow BRAT diet. Take enough liquid to prevent dehydration.