Chest pain. Am i having heart attack?

I am having burning sensation in stomach after eating. I burp a lot after 2-3 spoons of eating. . few times I experience loss of appetite ..  experience nausea as well ,mild giddiness is there . . I have vitamin D deficiency so I take Vitamin D supplements and fat foods such as fortified milk thick curd and few Almonds daily. I have mild left chest pain however I am not able to distinguish between heartburn or chest pain . .  I have pcos also. I have pain in left side chest/breast. What is the reason or cause of all these things??? I had knee problem from april so couldn't do rigorous exercises due to knee pain ,and instability of knee . Can I have heart blockage due to inactivity for 3 months.??? Am I having heart attack???