Hello! Thanks for putting your query in HCM. I am a Gastroenterologist (DM).
Take a proton pump
inhibitor like rabeprazole
along with a prokinetic agent like domperidone
in morning before breakfast and H2 receptor blocker like ranitidine
after dinner for better relief and to prevent nocturnal acid breakthrough as you have symptoms especially at night.
Diarrhea may be due to antibiotics you are taking. You haven't mentioned the name of that. If feasible replace it with quinolone like ofloxacin and also take probiotic
along with it.
Since the reflux appeared after intake of antibiotics so it appears to be temporary.
I hope I have answered your query and this will help you. If you have any further query I will be happy to answer that too. Remain in touch and get-well soon.