i know how painful bites can be, but we must not react to them. parrots are not aggressive birds of prey like a hawk, they are friendly birds. They do not attack, they defend. so if your bird is biting its 99% because of something you are doing to cause it. we, as humans, often always think we are the ones in the right, not the animal.
now, i will be honest with you....
what you did was absolutely horrible, there is no justification for it and i think you know that.
she is probally very scared now. what birds have to go through to get to our homes, they go through bird mills, ripped away from their parents months before its time, forced into crates and shipping boxes so crowded most birds never arrive alive, then they sit lonely in a pet store just waiting for a human to take them home.
they rarely trust humans and rarely have had a good experience, so for them to trust us is truly remarkable and a testiment to their courage and endurance.
She might trust you again, but it will probally take a very very long time, can you blame her? She thought she had finally found a human who loved and adored her and that human hurt her. It might very well be permanant and she might overcome it with your help.
from now on you must be extremly gentle and patient with her, she may start to bight ALOT and if she does then do not pull away gently move towards her. for example, if she bites your finger, rather than pull your finger away, which is the instinct, push it towards her, this wil cause her to release and will confuse her slightly as it is not the expected reaction and she will eventually learn her bites have no power, if you do this, and do not scream, yell, do not make any vocalizations at all when she bites, this will show her that biting you does nothing and she will give it up.
this wont happen in a week or a month even, it will take time and patience. http://www.goodbirdinc.com/
that is a very good site with a trained professional in bird training and handling.