It seems I may have created the categories “Literature,” “Movies,” and “Reviews” at one point for my blog then deleted them. Now when I remake those categories, it shows the slug as literature-2, movies-2, reviews-2. Is there a way to remove the “-2” from the slug? That tail affects category browses, does it not?
This is happening because you have tags with the same names but with a lowercase initial instead of a capital.
Categories and tags are the same kind of data. Never use the same word or phrase as both a tag and a category: there’s absolutely no point doing this, plus it can result in technical problems (as you found out). Check all your categories and tags for such duplicates, decide if you want each one as a category or a tag, delete the duplicates.