Okay, wired connections have less to figure out, so that should help. In fact, there are only 3 things here to consider: the printer itself, Linux Mint, and the cable connecting them. If you have a spare printer cable, I would swap it as part of the things to test (if no spare, unplug and replug your existing cable on both ends can help too). A fresh install of Mint tends to make me think it is okay too... it worked before for you without manually installing HPLIP. And a fresh install works for me too... I just now installed 18.2 fresh on a spare PC, and I did not enable networking so I have no updates or internet connection to get drivers. I disabled the wireless connection on my printer and used a standard cable to follow this process along with you.
1. With Mint running (and printer OFF)... I plugged in cable to USB and turned on printer.
2. A window popped up on my desktop saying, "Configuring New Printer" with options to Print Test Page or Configure. This windows disappeared after just a few seconds, and the printer worked. I did not even have to use the "Add Printer" app. It was that easy... again, with no internet so in my case it did not need to search online for drivers. I suggest having the internet working though, just in case.
So I tried something else after the above success, and got a failure too. Here's what happened...
1. With Mint running (and printer ON)... I unplugged the USB and I deleted the printer in the Configure Printers app.
2. Then I plugged the USB cable back in and I got an Error Window pop up... Missing printer driver for FAX (with a search box available that I did not use).
3. Checking the Configure Printers app showed that it did NOT install the printer either, not just the FAX.
4. But repeating this process again and it installed successfully again, even with the printer ON.
My drivers must be included with the HPLIP bundled with Mint 18.2, and yours may be too, or maybe not. But if you have the internet connected, there is little to keep your printer from working. It would be nice if someone had your exact model of printer to test with, but Linux and HPLIP are really very good with those printers that are supported, like both of ours.
It is possible that your printer died, just then, at a weird moment with the other things going on. I doubt that really, but strange things happen in the world sometimes. Can you print a test page from the printer's touchscreen menu?
Another step you might take, especially if you can print a test page from the touchscreen menu... is to look through the Setup section, maybe in a Tools sub section (where mine is).... and select "Restore Factory Defaults." You could browse around other sections to see if anything strikes you as possibilities (like it got put into wireless mode) but restoring defaults might tickle it into communicating over the cable as it used to do.
That's about all I can think of at the moment. Hope something here gets you on the right path. I'll be around today to try to check back, but starting tomorrow I will be very hit-or-miss while doing a little traveling for about a week.