Character cannot be hurt

Today I encountered a god mode glitch of sorts. My character is not able to take damage of any form but drinking poisons.

While in battle, enemies deplete my stamina. But no matter how long I allow them to attack, I do not lose any amount of health.

It also would seem that I no longer need to eat, as my nourishment does not deplete over time.

I’ve tried loading older save files and it seems that the glitch has infected my whole game, as even my first save file has it.

I’ve heard some say that the quest “A Rock and a Hard place” could have something to do with this sort of behavior, but as for me, I’ve not touched that quest yet.