To the person who feels like they don't have a place,
Know you are not alone. There are some hard days and maybe some more ahead, but every obstacle leads to better times. Start believing in yourself. Start believing that your life isn't hopeless, useless, or a waste. There is so much here for you on earth and so much this earth can benefit from you.
When times get hard, take a deep breath. If it seems like no one loves you or cares about you, realize they do. Ask yourself if you are really allowing the people around you see how you are suffering. It's easy to say "no one understands" when we are hiding what is torturing our thoughts. Our loved ones are not mind readers, so open up to them with your struggles and let them be there to guide you and support you. Then, you won't feel alone.
When you feel like the world doesn't have a place for you, try volunteering. Go to a children's hospital, an orphanage, the Special Olympics or some other great organization for those who truly face the challenges of life. See people, many of which children, suffering from aggressive diseases, are victims of neglect or abuse, or those who were born with special needs that require extra day-to-day care and how they have all manage to get up every day and see their place in this world.
At times when they may have felt they did not have a place, their strength and courage to face obstacles gave them the place they deserved. When life has thrown hard obstacles their way they've chosen to see that as a positive aspect of their life.
Look at some of your friends, loved ones, classmates, and so on who may be considered "different." Those who may be labeled as weird or strange. People who identify as one gender, transgender, and so on. Look at the daily struggles these people face with having society understand their identity, yet they still continue to see their place in the world as who they are no matter what others say. When everyone is trying to tell them they can't be who they believe they are, they still wake up every day being who they are.
I'm not saying to toughen up because people have it worse, but I believe the best way to start pulling yourself out of a dark place is by realizing all the positives within your life. When personal struggles hit, many of us (including myself) fall into the habit of self-loathing and depression. We think the world is against us but I promise you it isn't.
Give life a chance and it will give you so much more than you can imagine. So when you are down, look at those who take their low points and make them their strengths and try doing the same. Search for the light at the end of every tunnel instead of moping around and thinking that a better day isn't ever going to come. It will come with time, hope, and strength.