Steemit Bandwith problems: A quick question to the experts

Dear steemians,

For a short time, I was unable to post, comment and reply on steemit. I got an error message regarding bandwidth. Looking on steemd revealed that my remaining bandwidth was negative (minus 20.54%).

Can anybody tell me why this was the case? I did not post a lot prior to the error message. Is it related to my previous posting behavior or does steemit have bandwidth problems?
Do you know how I can avoid such problems in the future or how to solve such problems?

And when you are at it, can anybody tell me how long it takes for my voting power to recover? Is there any rule of the thumb?

Appreciate your answers, thanks a lot!!

Best wishes,
Chris