Il mio capo mi vuole morto!

If you think your evil boss is overloading too much and you already tried with HR (without success) and the local employee support program (addressing to a psychologist suggesting to quit the Company and suit for mobbing)... may be you want to try the best "superhero" around: yourself. This is basically the suggestion of the Evil HR Lady (Suzanne Lucas) from BNET is giving:

Write down a list of your current responsibilities/projects/expectations.
Sit down with your boss and go over your list of responsibilities.
State clearly and firmly that you cannot accomplish all of this in the time allotted.
Ask her to prioritize your work load.
Ask for an explanation of how she wants you to accomplish what she requires.
Shut up and listen.

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