I’ve done this a couple times, haha. There are a couple things you can try:
Go into your main OS drive (probably C:) and look for a Windows.old folder. I forget the specifics, but you could have your entire user folder (Documents/Publii!) in there.
I’ve also used Recuva to recover some deleted files with a little success. I was able to grab some important files – theme’s config, etc. Only works on an actual hard drive, not an SSD. I’d also do this ASAP as the more you install/use/download, the more likely it is you’re overwriting your old files.