As your link clearly states:

> An [automatic filter](http://meta.stackexchange.com/questions/56817/can-we-prevent-some-of-the-low-quality-questions-from-entering-our-system/60294#60294) is in place to ban questions and/or answers from IP addresses or accounts with a history of *extremely* poor posts. 
>
> Once you have posted too many poorly-received questions or answers, you will be banned from posting more, and you will see the error message.

Basically, you've been IP banned.  If you're at a school or business (or even at home), it may be someone else there who has deserved the ban.  If it wasn't you making all the rubbish questions, you may be able to try again from a computer with a different internet connection.