As I was moving my cards from Core 6k to a different vocabulary deck, I somehow accidentally deleted all of them (1k cards, all mature). I have a separate anki deck where I get vocabulary from other resources like the news and such, should I be worried? Fortunately I have all the words I've studied in a notebook of mine, but since their already all mature (the next interval was about 4.1 months), should I bother putting them back into anki?

I don't know most of the options in Anki, so there might be a better way, but something that might work, is that if you had uploaded the deck to Ankiweb, you could synchronize the deck and DOWNLOAD the previous copy, rather than upload it. I think when there's massive changes the program detects the changes and ask you which version do you want to keep. You can change the deck EVEN MORE to make sure the program will open the pop-up, like changing the format of the flashcards.

Set up sync, so that the next time this happens, you'll have the option of getting them back.

You could start over with Deck->Options->Easy interval=45 days or something.

I'm just going to set up auto sync for now on. I'll just keep adding vocabulary words to my anki deck. I might end up keeping it in my long term memory without anki as I encounter the words fairly often.

Load the automatic backup.

^

Documents\Anki\User 1\backups

A week or two of backup data is provided in the form of .akpg files, or decks.
Open the file as if it were a deck and it restores your data.

Oh my, thank you so much!