Hi Finnegan, welcome to the forum! Let's start with your emails, which may very well still be in your system. The problem of course, is to find them. One of your options would be to go into Outlook and do a search from within Outlook to see where on the system those specific emails are being stored.
Another option would be to do an Advanced Search for all of your emails through Windows.
You can't go directly to Advanced Search. Press the Windows Key + F (or go into the Start Menu, and from inside the Search pane, press F3). That brings up the Search page, then click the Advanced Search button to the far top-right, to open the Advanced Search Set-Up page.
To narrow your search to locate only emails, at the top of the screen, go to Search Only, and check Email. Under Location, select Computer, or Everywhere, and in the Name box, fill in the name of the email you’re looking for, or some key word that will identify the email. Be sure to check the box that says: 'Include non-indexed, hidden, and system files.'
Click on the Search button, and when the emails come up, if you single -click (highlight) them, you will be able to see where they are being stored. (Or check the "Location" column heading.)
If the emails are being stored in multiple locations on your system, you can do additional searches, using any other key words you think might be associated with your emails --- until you locate them all.
In regard to your other types of files, to locate them, you would use the same Advanced Search method, with the only difference being that instead of just limiting your search to Email, you would make another selection of file type, (i.e. Documents), or you could choose All and search for everything at once. It sounds like you've got a big job ahead of you, so perhaps if you do it bit by bit, it won't seem quite as overwhelming.