Can't upload pictures

Hey Guys! D

First of all: Thank you so much for over 1000 watchers.

Second... I'd actually want to upload more pictures but it seems I can't.
Whenever I try to upload something the categories won't finish loading. °-°
So everytime I hit the submit button it tells me I have to select a category, that's happening for a while now and I'm seriosly at a loss.
It can't be my internet, though, because I have a very fast and good connections, but it's also not the browser because I tried out different browsers.
Has someone experience with this?
It's very annoying because I have a bunch of stuff I want to show you... v.v Uguu
Little help please? ;;