If you're putting in too much effort trying to keep someone in your life, then those people aren't exactly a good influence on you. They are not the last you will meet. You are so young and there are so many people around you can meet. Therefore, you do not need to destroy yourself just because you have not yet met the very person who will definitely love you and take care of you. For now, take care of yourself and be brave enough to cut out of your life those people who cause you more pain than joy.