I have other signals that creep up when my background anxiety levels are high. By anxiety I mean nervous system agitation, not usually conscious.

I wash my hands more, engage in displacement activities, avoid unfamiliar situations or those that trigger perceived emotional stress or threat.

I become snippy and agitated, again, without being conscious of it.

My HRV matches my partners perception of my anxiety levels, which is a reliable measure imho. When it becomes unbalanced and I reflect, I can see that the other signs have ramped up.

If I'm not aware, or told, my HRV tells me and saves anyone pulling me up.