Ah, right. I have like 240 health. Could this be the issue?
I don't know why you wouldn't have had a problem before. 100 AR and 240 health at level 81 is very, very tiny. Big threats can easily kill you in one hit like that. It should be happening with more than arrows, honestly. I have a level 61 guy almost at the armor cap and I have to keep increasing my health past 400. I think around 500 I'll be pretty good. When I had less than 300 I would encounter guys who could kill me quick. Of course, I could kill them quick too, so the problem wasn't always obvious.