as someone with health anxiety, i totally get you!! when i first got an apple watch i couldn't stop checking my heart rate and it was always ~90 even when i was sitting down and doing nothing. i was really worried and kept checking it and it even reached 100 at some point (yea i was scared shitless i really thought i had Serious health problems) but then i got distracted by something i had to do and forgot about it for a bit. checked my heart rate history afterwards and realized that when i didn't check it constantly, my heart rate was usually in the 70s region which was perfectly normal. so i'd say it's probably associated with anxiety too tbh