I'm at an age where a heart attack is a more realistic worry than at your age, but there are a few things that might reassure you. First, get bloodwork done, if you don't have bizarrely high cholesterol and don't smoke, or some very unusual family history of really early heart attacks, its pretty much impossible for you to get one at your age. Second, I had the same fears and sometimes still do, I remember when I first had panic/anxiety at 31 I got a stethoscope and when I would get a sharp painful feeling in the middle of my chest I proved to myself it was gas, I could hear the gurgling with the scope. I can sometimes get stomach gas now which can cause quite a bit of pain, different than when I was younger, and which can radiate to my back, but if I drink a lot of water, guess what, I burp out some gas and the pain immediately vanishes. So your fears are not uncommon for anxiety sufferers, but after getting appropriately checked by the doc, your logical mind should tell you that you don't have a heart problem. You do have an anxiety problem and that can be dealt with by either therapy and/or medication--its our brains that are malfunctioning, not our hearts. BTW my father had his first panic attack at 23, was convinced for about 9 months after that he would drop dead any minute, and didn't have healthy habits, but he lived to be 83. He never thought he's see 40. So you will be around a lot longer than you are probably thinking, and anxiety is the likely cause of the pains you are suffering, it can be an amazingly physically painful/symptomatic condition, but it will go away eventually.