In view of your symptoms I think you are having gastroenteritis
. Usually cause is either viral or bacterial. Usually treatment is directed towards maintaining fluid and electrolyte balance.
Maintaining hydration and electrolyte balance with increased oral fluid intake and some salt may be helpful. You can take Ready-mixed rehydration sachets (eg Dioralyte, Rehidrat)
) may help reducing intestinal motility and give symptomatic relief. Oral antiemetic (Pepto-Bismol
) can help controlling vomiting(if you have it). And if symptoms persist a stool culture and course of antibiotics may be considered.
And as you mentioned your are very weak at present i think you are already dehydrated and you should consider seeing a doctor sooner. And blood in stools is also cause of concern.