Burning Chest Pain, Syncope, No Fever, No Energy, Cold Fingers. Ranitidin?

Hi! I m currently experiencing burning pain around my chest , heart and solar plexus. I fainted last wednesday after a workout at the gym , i m pretty healthy overall and workout regularly. I had just been sick and gone from training for 2 weeks, so it might have been a hard start. I spent the night over at the hospital where they did blood tests, EKG , AKG (bycycle test), and everything seems to be good with my heart. I got the diagnosis Syncope . Few days later i did the same program and almost fainted again after the workout, but i layed down for a while (45ish mins) and got a little better after i drank som saltwater. Now i still have this burning feeling around my chest. I have to add that i have had gastritis last year, and it has come and go. Might this cause the pain? Should I take ranitidin tablets or should i be more concerned? Because my fingers are cold, but I have no fever, and my body feels slow and dull, tapped for energy. Need help ASAP please! Regards,