I imagine you have had some judgemental responses but honestly haven't read any...
I have done things I didn't mean to in anger. Beating yourself up only serves a purpose if you are willing to get passed the guilt (accept your faults and really start tackling it with a "tool box").
Have a list of behaviors you know are off limits to your goals as a parent, and I imagine hair pulling is now on your list, and don't go there, ever. Same with teaching a child to lie. It is always better to walk out and slam a door if necessary.
Medication has been enormously helpful to myself and a relative when it came to anger and parenting, strangely enough depression is our culprit. Both of us are enormously relieve at the edge that was taken off by medication.
that is tool number two.
Read some favorite/recommended parenting book, a few pages every night before bed... I always parent better if I read and reflect in a non judgemental way every night. Remember guilt for the sake of feeling bad about yourself is useless, it won't help you or your child.
Drink a glass of water when you feel a boiling over happening... drink the whole glass before you let yourself speak...
Develope further tricks to stop your anger from moving forward uninterupted.
Put them in your tool box.
Have safe GD friends to get ideas from (the hardest part of all, I hope you have found some help here)
Also you need to read Drama of the Gifted Child
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