I'm really confused and a bit anxious about this chest tightness that happens whenever I lie down flat or stretch my left hand. It's been going on for about three months. I went to an orthopedic doctor who said it's probably due to poor posture and muscle spasm. Then I saw a cardiologist, had all the tests like ECG, echocardiogram, TMT, and even checked my cholesterol and BP. Everything was normal except for my cholesterol which was a bit high at 196, and LDL at 121.8. The cardiologist said I don't have heart issues and just need to change my lifestyle and lose some weight. But I wanted a second opinion, so I visited another cardiologist and even without any new tests, he said the same thing that everything's normal. Still, I feel this tightness at night and sometimes it makes me sweat and I get really scared thinking it might be a heart attack. When I went back to the cardiologist, he reassured me again. So, should I keep doing ECGs every time I feel this tightness or maybe see a pulmonologist? Why does this keep happening if everything's supposed to be normal?

since your age is not too much i suggest reduce your anxiety related to heart attack. try doing some exercise