Pain upper chest & back while eve walk.

It started with a bad episode of acidity, regurgitation, burning sensation in mid chest after meals( date 5 March).i walk 1-1.5 km daily in evening, started having pain in upper chest wall and back while walking(date 9 March ), it got fine after rest.no pain during day time daily chores like sweeping ,picking up buckets .The pain episode in evening were followed by flatulence and bowel movement ( minimum once on all days) . After 4-5 days pain episode(,one episode of severe throat pain while walking occured)  went away just the heaviness in chest remained.took pudin Hara and carbonated drink.heaviness went away but back pain still remains. No discomfort during morning brisk walk ,daily chores or on stairs.but flatulence burping and bowel movement in evening persists.had racing heart attack twice with a gap of 3 days ( 11 and 14 March).Vit d level 8 ,b12 -100, in Dec 22.took supplemens for 3 months..no supplements now