So the application started crashing, so I closed the file. When I reopened it they let me recover the file, so I saved it as my own thing, but when I went to the 'open recent' tab it wasn't there. Then when I tried to look for it in my folders, it wasn't there at all. Is there any way to get it back, and if not, what exactly happened?

Which Operating System and which version of krita are you using?
If krita was 'crashing' then I'm surprised that you were able to close the file or do anything.
When you saved it "as your own thing", where did you save it to, as what filename in which location on your hard drive?
Have you previously saved .kra files to that location before with no problems?