Stomach fullness after small meal. I do?

1st Hello recpected docs, every time I eat food even in small quantity I feel fullness of stomach. No indigestion issue as such .No other symptoms like Nausea, vomiting. Now a days I face loss of appetite also. Even after having tea it seems I have taken food. After eating meal I feel heartbeat on my stomach.If I eat more food then it is increased when I am at rest condition.At empty stomach or rest of time I never feel this beat on stomach. I am facing lack of concentration also. My wt is 72 kg and height 5.9 feet. My body is lean. What I feel  It may be due to gastroesophageal reflux uneasiness and anxiety (which I had experienced i past). Seeking suggestions and advices from the experts available at this platforms. Both the issues are faced from last 1.5 yrs.What should I do? My ECG , BP and Lungs seems well.