That is part of the dark side. All those feelings, hate, anger, lust and so on have one thing in common. They grow the more you give in to them.
That is why she would tear the galaxy apart. She has fallen into a similar state like Nihilus, hunger. Only her hunger lies not in destruction but in her own satisfaction.
She wants to prove that she is right, that her teachings are right, that all she has done is right. She wants to show the Jedi Council that they were wrong to betray her. Her lust for victory lies in proving them wrong.
And when she proved all of the council how superior she is, she has to prove it to her student and herself, as with destroying the will of Atris she gained nothing but more hate. That hate is no longer directed to any person, as no one is left except the Exile. And she can't hate the Exile as she envys him/her for the ability to cut oneself off the force.
She can't cut herself off the force. The force would be all around her. The only way of her getting herself seperated is destroying the force itself or getting destroyed by the Exile.
Ironically, the more she hates it, the more she uses it, so she is really blind.