I´ve been using the same Apple Id for the last five years, but now it doesn´t work... I´ve tried everything, please help!

In what way does it not work? When using iCloud? When accessing the App Store or iTunes Store? When signing into the ASC forums? Please explain.

As long as we do not know exactly, what your problem is, have a look at the "Learn More" on MyAppleID:

Apple - My Apple ID

Regards

Léonie