Pain in left side of the chest. Heart?

Hello Doctor, It's been 1.5 years but still could not find out what the problem in my body. Initially I started to be more anxiety & get panic attack due to one of the video which I watched i.e. people dieing in heart attack. So met doctors and took ECG,Echo and TMT all came as negative. These are taken 1 yr back but still have pain on the left side of the chest sometimes radiates to my arm mildly. Every time when I get palpitation increases I rush to ER and they take ECG & confirm I am normal. I m attaching my recent last two ECGs for the reference. All my question is even after taking abdomen scan,ECG, Echo etc all say is everything is fine. Then why should I have this uncomfortable pain in the chest. One thing is confirmed while I gone for endoscopy that I have gastric. Will gastric cause this much problem? After eating pain increases. How to confirm this pain is not related to heart? Note: I am able to climb staircase without any difficulty. Even able to stretch my arms towards up.