What should a son do with his parents who are harsh with him, treat him like a child, and hit him when he disobeys them, while they do not hit his older, immoral brother, and his mother, whose prayers are answered, invokes curses upon him?

You must be dutiful to your parents, obey them, patiently endure their harm, and avoid anything that provokes their anger, for Allah Almighty says: {And your Lord has decreed that you worship none but Him, and that you be dutiful to your parents. If one of them or both of them attain old age in your life, say not to them a word of disrespect, nor repel them, but address them in terms of honor. And lower unto them the wing of submission and humility through mercy, and say: "My Lord! Bestow on them Your Mercy as they did bring me up when I was young."} If the situation persists, you may address it with them politely and respectfully, and seek the help of your relatives. As for your parents, they should not strike you as long as you are an adult, and they should be fair between you and your siblings in giving and showing mercy.