Woops, I can't change anything Options

[katarina]

First of all, i'm sorry for my english, it's not my first language.
In last few months i have some problems with my tumblr. I can't change my music, theme, description or avatar. I go to my playlist and change songs, then i click update preview and then save, but it can't be saved. It's loading and then woops, try again later, and i tried it like, million times from my computer, from my lap top, even from my friend's computer, because i thought that something is wrong with my internet speed and it's been like that for four months. So, does anyone knows what is the problem?