Parents obedient is limited to the things that they say which conforms the the law of sharia, if however they ask you to do anything against god then you should never ever obey them. Obviously your dad in that situation was practicing zulm (oppression) against you especially the physical abuse he should have been reported to the police and not obeyed , in order to stop his aggression against you. This kind of dad does deserve any obedience in fact if there was a proper legal system he should have been incarcerated to protect you against his aggression and abuse.
You are under no Islamic obligation to obey him and no you are not going to hell fire if you don’t.
Having said try and get counselling for you mental health so you can lead a normal life and get on top of the trauma you have suffered from. You must seek every possible medical and mental health to restore your confidence and claim your life back.
Father’s are meant to protect their kids not abuse them.