How to believe in yourself? Develop humility!Try to accept your present situation whatever it may be. You must be completely at peace with what your life looks like at the moment, as well as with the things that have led to this particular situation. You can never, ever achieve anything if you suffer from what you currently have.
Don't let fear stop you!Fear is what hides behind the false evidence of what seems real to us. And it actually keeps us from believing in ourselves more than anything else. You have to learn to face your fears and by no means let them stop you from achieving your goals. You have to always do what you are very afraid to do. You need to be able to enter your fear, and only then it will begin to recede.
