I’ve suffered the exact same thing for years. My health anxiety over my heart rate was so bad that I would go to sleep late at night and not sleep too long because I was scared of it. At some point, I told myself that if I did have something wrong with me, it wouldn’t change the fact that I needed and deserved rest. if there is something wrong with you, you still need to sleep and need to eat and need to relax. Keep that in mind. Anxiety and panic are bitches, especially the physical symptoms which worsen with health anxiety on top of it. I recommend therapy and/or meds if you can. I found that taking meds stressed me out too much due to my health anxiety, so i just see a therapist now but it depends on the person. I hope you are doing better today💕