Dear friend, welcome to HCM.
You seem to be having a gastro enteritis- bacterial or amoebic.
If not better with the medicines you mentioned, please get CBC and stool routine, and serum electrolytes done. If shows infection , get stool culture done.
You may need anti amoebic like metronidazole
with an anti bacterial like norfloxacin
Please see another doctor who can prescribe these and the tests.
Drink lot of boiled cooled water.
abdomen may be needed.
I hope to have helped you out.
Keep me posted and Good Luck !!