Thank you! After the [Christmas] event, my healers plan to look at every single line of my character's source code to look for bugs. I thought only the devs could do that, but the healer's guild figured it out somehow.

I am happy to hear that the original debuff was just an impostor! Getting out of a sticky situation with low HP always feels good! There are items one can buy that will help with walking; perhaps you can look into those? They should be available from the Auction House or similar markets. Hopefully, you’ll slowly regenerate HP and your walking ability! Enjoy the christmas event that is comming up! Stay safe!

5 months on, I do have some good news about my character.

My healer encouraged me to see another healer who has better items. The new healer was able to determine that my character doesn't have the debuff the first healer thought it did.

The healers still don't know what's wrong with my character, and it still can't walk, but my character may not be running out of max HP.

I'm sorry you're dealing with this debuff. Sounds like a rare, persistent DoT that ignores all the usual cleanse mechanics. I know that higher level priests exist, but some charge quite a lot of gold for their services which can be a problem for those who aren't as good at farming gold as others.