How to tell if you are stable or getting worse?

It's strange, because the past few weeks I felt alot better emotionally, my sleep improved and I also had less symptoms, but I track my symptoms with the visible app and my HRV and heart rate have been getting worse alot and it warns me everyday to take it easy.

Also it feels like my heart is working very hard and it's pounding / racing constantly. I had a 24h ecg which was normal.

I didn't increase my activity and I am already "radical resting" 90% of the day.

I can't tell if I am in rolling PEM and don't know how to find out.

What do you find more reliable: symptoms, heart rate or how you are feeling? How do you know if you are getting worse or better? I feel like resting as much as I can doesn't change how I feel at all.