Welcome to PC!!! Can you ask your brother for help? Like sharing the responsibility of taking care of your parents, lift some pressure off your shoulder. And your mother may not notice how depressed you are because you are acting normal in front of her? If you cry, she would surely ask what's wrong and care about you right? Sometime when you feel low, you would think negative about everything, to people, to yourself, to the situation. Talk with them, with us, would make you feel alot better