You matter and don't ever think otherwise! If someone tells you that you don't matter, remember that they may also be thinking that they don't matter so they express their anger and hatred of themselves on you. Remember that they may not mean it and even if they do, it's not true. You matter. You are part of the world. You are part of someone's life. You have a life. You matter, always and forever. Your life matters.
People have been killing themselves because they believe they aren't enough. They believe that they're life and themselves don't matter. Sometimes they don't have anyone telling them that they do matter. I want to tell those people that they do matter because they're part of our world, they're important in someone's life but they might not know it, and they have a life to live for.