As a Muslim, when is it okay to go against your family's wishes?

Assalamu alaikum everyone. I lost my dad when I was young, and while my mom and brothers are practicing Muslims, honestly, they haven't been good to me. They've caused so much unnecessary stress, anger, and trouble that I developed a health condition from all the tension-I'm still dealing with it now. When the doctor explained it was stress-related, they reacted by saying things like, 'Oh, so we're the bad ones making you sick?' Subhanallah, now I can't even sleep peacefully; I'm scared someone might wake me up at 4 AM to yell or threaten me, even though I'm unwell. If I think about leaving home, I'm worried about three things: first, finances since I just finished high school; second, my mom getting so upset she might curse me or fall ill from anger; and third, fearing Allah's displeasure. Please, any advice? This situation is really hurting my health-I sometimes feel numbness in my limbs and head from the stress, plus the inflammation and heart issues it's causing. What should I do?