Note: I do not have vamparism and I unequipped all of my items and armor to see if it would change anything. It didn't.
I've just noticed an issue where my health depletes in large increments after a few seconds when entering a new area. I watched it happen while exploring a cave, and it happens every time I fast travel. I don't know what the issue is, because I've never had this problem before. I fast traveled to a town and when I spawned I had almost zero health. I searched it up on Google but I never found the same issue as other people. I'm not really sure on how to fix this.