Deleted entire Mods folder, localthumbcache file doesn't show up.

Vikygame1  It sounds like you're not using the folder Sims 4 is actually reading.  Here's how to find it:

https://sims4.crinrict.com/eng/2018/07/how-to-find-your-user-folder/

You also shouldn't have to create a Mods folder on your own, and it's best to use the one the game creates anyway.  So don't delete that one, just add your mods to it, a few at a time.