I don't need to be a doctor to know he's sick.
But that doesn't help you now. You say your mother didn't tell your father about your brother hitting her. Is there anything stopping you
from telling your father? And if for some odd reason your mother doesn't want to tell your father she's been hit, you can always tell him you've
Although if your father is paying any attention at all, he should have figured that out by now.
This is not going to get better by itself. Your brother's height is his height-- and if it doesn't reach some magical number where he thinks all of his dreams will come true, he's going to take it out on everyone. Which he does already.
I fear he is going to permanently injure one of you, and soon.
Making him apologize hasn't done ****. He needs treatment. And I recognize that in an Arab country, that may be nigh well impossible.
Since you're close to 18, can you get away at all? Stay with relatives, go to school in another town, get into a remote college, share an apartment with girlfriends and go to work, something like that?
Conditions are deplorable. They won't get better without radical changes. Since those changes are unlikely, start planning your escape.
And once you have well and truly escaped, I hope you can at least pull your little brother out.
This is no way to live.