Stomach gas and fullness after small mea

I have been facing issue of gas from past 3 months. My eating capacity is half now and weight has been reduced. I lost appetite and gas used to come up in food pipe and constant urge of spitting happened. Now I am taking ganaton total, aristozyme, librax and multivitamin. Now the issue is that I can't eat large meal even if I have strong Appetite. If I increase my intake even half chapati more I get bloated and gas is created. What to do? I have been taking mentioned medicines from past 10 days. I have anxiety issue also like I think alot. Please help me find perfect solution or any test needs to be done to diagnose anything. I have been through barium swallow and endoscopy both are normal. CBC, THG, fasting blood glucose, BP everything is normal.