Welcome, our DTC Lookup page gives you a general description for each:
https://www.ecodieselram.com/forum/pages/dtc/
But, I'm not familiar with them enough. I would try clearing it once, and see if it returns.
Welcome! Sometimes it's just not meant to be. As far as bad fuel.. I'm not sure how'd you'd claim the station responsible if you went that long with no issues... keep us updated on what you figure out. Maybe get a sample then call corporate, they have insurances for that.
At this point, it might be worth it to have the dealer check it out. I did read if you're in warranty or not.. if you are, for sure take it in and see what they say.
This might help: https://en.m.wikipedia.org/wiki/Diesel_particulate_filter
We also have tons of reading here about regen and how to manually perform one with the right tools. This might also help: https://www.ecodieselram.com/forum/threads/exhaust-filter-100-full-service-required.1613/
Is that website legit? Looks a little scammy to me. FCA had to known this was coming, and would of have time to develop some kind if "official" website rather than that garbage.