category searching is slow

[Guest]

when loading the website, there is absolutely no (or not much) difference between having 1 category/subcategory and thousands (like i do)

 

for my type of site, the amount of sub categories i have makes more sense than grouping unfamiliar products with one another...

 

but when i search in my admin, it is notoriously slow. how can i speed it up?

i am using the default categories search in admin