I walked by my 30 something year old jade plant and exclaimed in not so polite words, "what the heck!?". The leaves are, well, not sure how to describe it. See attached photo(s). It's spotted. Doesn't look good. This poor thing has gone through a lot in its lifetime. Early fall it got attacked by caterpillars, now this.

Can someone tell me what happened? What is it? It's been in the same spot for about 3 months. It hasn't been watered in a while ... Is it eating itself? Is something else eating it!? Omg! Help! It got pretty cold last night. But it was my understanding they're reasonably cold hardy plants. (It got down to upper 30's but no frost).
Help?

Google has not helped ... What did I do to this poor thing?

There are two clues to support your suspicion that it got too cold and is a little frost-nipped.

1. You haven't watered for awhile. A plant can withstand more cold if it is well hydrated.

2. All the damage is on the outside leaves - the inside leaves were protected.

Your zone is a little too cold to leave a Jade outside all winter. But, if the temperatures were in the upper 30's when the damage occured, my guess is the plant wasn't watered sufficiently to stave off the cold.

The good news is that it will recover and be beautiful again. Unless the catapillars come back...

Thanks Daisy. It was you and tarev that walked me through reporting/dividing this spring. Thank you for the pat on the head and "everything is gonna be alright". I'm gonna water it real good and bring it in under a light for the rest of the winter. Thanks again Daisy.

It looks more "eaten" than frost bitten to me. In any event, no serious harm done.

The "pitting" of the Jade leaves is usually caused by something physical rather than cultural (watering, disease, etc.) It may be cold damage or some kind of chemical spray or water droplets magnified by the sun. Unfortunately, the pitting is permanent on the affected leaves. Once the source is identified and eliminated, new growth should be fine, as is the overall health of the plant.