"Should it correct itself or have I done irreversible damage?"
If you did overtighten, you did not hurt the frame as it's made to flex. The door should align itself again. However, if the paneling in the camper came loose, or nails or screws came loose, those will not self-correct. Everything should align itself, but a screw won't re-tighten itself. Hopefully nothing like that happened.
It NOT uncommon at all for the doors to be out of align when one jack is over tightened causing a flex on one corner, especially if you are attempting to level on a sloped parking spot. After 30 years of camping, several campers, pop-ups and such, we still sometimes have problems getting the outside door to shut smooth, it wants to drag at the top or the bottom. It's always because one jack was tighter than the rest. I don't think you hurt anything, after all, they are made to actually have this 'flex'.