I get a lot of belching after having my food and feels as though my stomach is full around 2 to 3 months. night times I dont feel hungry much. i do smoke, but alcohol once in a month, not much. And I dont do exercise, this has resulted in a big tummy. Some days back I was taking, but have stopped it now, some medication before breakfast, I dont know the name of it
With your complaints, I can think of a common problem called acute gastritis with reflux disease which can be confirmed with physical examination and few tests. The causes are overweight, smoking, irregular diet too many beverages.  So please cut down your smoking and no beverages for some time.  Take regular bland diet without many spices. Cut down the smoking to 2 per day. No beverages for one month no milk products like cheese chocolates, ice creams.  Put two pillows while sleeping take only lite dinner. You should see the change in 15 days.