There will be lots of times all theses will get at you, making you feel sad and filling you with self-doubt. There will be days you will lose your self-belief and feel like the obstacles are too many. And there will be days you go on autopilot, just hanging in there without any motivation. There will be moments you'll feel all your goals have turn to mission impossible.
These are the times you lose your confidence/belief in yourself. You feel despondent. You lose the drive that has set you on the path you are on. You feel inadequate. You feel life is very unfair. You are just not happy.
The truth is you need to put your confidence/belief in yourself above the reach/influence of anyone or circumstance. How you see yourself matters way more than the situation life has put you in. You can't change anything by being sad and unmotivated. Your best can only come out when you have a strong confidence in yourself. And you increase your chances of success and improving your lot by constantly being motivated and giving your best.
You have to believe in yourself. No matter the situation you are in. You have to see a chance of succeeding no matter how faint it is. If the results you are getting are not good enough, being despondent will only make them worse. If life is not going your way, giving up will not improve things. You just have to be crazy enough to ignore the reality that keeps hitting you in the face. You have to see what is currently not there. You have to see the lion in you. You have to keep believing in yourself.