Welcome in H.C.M.
I have gone through your query and after Considering all aspect of your medical history and the effect of medication it appears as most likely you are having-
1- Antibiotic induced diorrhea.
2- Irritable bowel syndrome
3- Intestinal infection.
To differentiate and to confirm it you have to do-
a- Stool examination for parasite.
b- stool culture and sensitivity.
Till your investigations are awaited you may take Probiotic
/ lactobaccilus tab to get relief from abdominal problem. At the same time consult ENT specialist
to rule out local cause of severe and chronic cough
and it's management.