How do you cope with life when you're alone and there's just one person who loves & understands you?

Love: It is very difficult to only feel loved by one person. Try joining group functions, book clubs, exercise classes, cooking classes etc. Some experiences that expose you to other people. If you find this difficult consider consulting a mental health professional who can help you uncover the anxieties you may have interpersonally and help you learn interpersonal skills that will help build friendship.