Ah, the vampire thing is interesting. Thanks for the reply and confirmation. Seems like it's more than not that something just eats at the health, like the campfire lol. Perhaps that was a part that I hadn't reset it, but I could have sworn it was enabled. Oh well. Thanks again.
I can confirm from experience that certain environmental hazards (Falling, campfires, poisonous vapor, etc.) chunk your health at a set percent of max per second of exposure.
I had to continuously hammer the option key if I got caught in, say, the poisonous gases of a swamp in Velen, or hilariously enough if I stepped too close to a beehive without setting it on fire with Igni.
Also, falling more than 10 feet instantly kills you regardless, so there's that too.
Seems these forms of damage are scripted to do a percentage of damage instead of flat damage like enemy attacks. Falls seem to do an increasing percentage for every foot you fall past 5 feet, up to an instant death at 10+ feet.
Your items disappeared probably bcuz you left on the F-11 Gwent option. That's done that to many of us playing W3. Turn off F-11 when finished with Gwent, leave the inventory screen then go back and you should see your items again.
There's a good chance that's what's causing it.
[Edited by Jakshyt, 6/18/2017 11:30:18 PM]
You can change the value of some options to what you want, like health for instance.