Aware of heart beat

[stars22]

I keep getting big odd thuds in my chest well after that my hr was 132-106 for nearly three hours then this morning I woke up with discomfort in my chest and back so I checked my hr it was 62 -74 depending laying down to sitting this morning I can feel my heart beat and my chest feels it keeps going tight I've checked my hr it's 85 bpm ....
I feel like my chest is just gonna lock up and my heart will just stop I have nightmares every night now and I'm obsessed with checking my oxygen and heart rate on my ohone my chest is constantly tight and pounding or my breathing feels effected I no longer can go anywhere for more than a hour without ending up with racing thoughts taking over

[Shazamataz]

This sounds like an anxiety symptom to me. But I am not a doctor - have you spoken to a doctor about it?

I have similar issues though my heart rate is never as high or low as yours. I often feel it thumping when I lie down.

Checking makes it worse as does paying it attention, but it sure is hard to ignore!