I am sure you have heard this countless times. And you probably think that it is pretty much an overrated quote or advice. But there is all the truth to it. No one else is going to believe in you as much as you potentially can. That is due to the simple fact that no one could have as much vested interest in you as only you can.
It is with sheer believe does one achieve great things. Pretty much if everything else is going against him, that self-belief is the only differentiator between someone who can make it through or not. Ignore what those naysayers are preaching, that self-belief alone will not cut it. Rather, it in itself is the foundation and baseline for all successes. So if you are having doubts on your future, do yourself a favour and believe in yourself. Believe in your capabilities. Believe in your dreams.