Understand that not all of your friends and family are supposed to believe in you. may be they were not supposed to believe in you in order for you to believe in yourself first. Just because someone you love and respect (or somebody powerful) doesn't believe in you, that doesn't mean that you are not worth believing in or not good enough. Leave that mentality behind, see yourself from your own eyes. Don't let story of 'no one believed in me' be the only reason why you don't believe in yourself or why you don't reach your highest potential.