Why Am I Having Gas, Burping, Throat Itchiness, Coughing, And Stomach Cramps Despite A Light Diet And Taking Metformin Daily For Type 2 Diabetes?

Hi, i m a type 2 diabetes and take everyday a metformin with 850mg after breakfast, my concern is every night I fart alot maybe 5-8 times every night and during daytime I m burfing a lot after drinking water or eating my meal. And sometime my throat are itchy and need to cough. Sometimes also i have cramping pain all over my stomach a bit of pain like some nerve are tickling. I m eating a small diet now and more on vegetables and fish.