Am I allowed to leave home and run away if my life is an unbearable hell?

We cannot advise you to stay or leave without knowing the reason why you described your staying at home in that way. In general, if both or one of your parents are alive, continuing to live with them and taking care of their affairs is better, unless you fear for your religion due to the family's corruption. In that case, you may leave the home, fleeing with your religion.