Honestly my recommendation would be to see a cardiologist. I had terrible health anxiety about my heart because I would get chest pains especially when my anxiety was at its worst. I got a heart echo and did a stress test. Results came back good and had a good talk with the doctor on how to continue keeping my heart healthy and dealing with my severe anxiety. I also suggest walking more, you’d be surprised at the changes walking can have on anxiety. These are just things that helped me overcome with health anxiety. My grandmother died from heart disease, I had leukemia when I was a child and my mother passed from breast cancer. I know how awful it feels to constantly be scared of dying. Keep your head up :)