Whenever you set out on a journey towards something there will most likely be times where you run into a wall. Whether it is internal or external, no journey worth doing will be free from adversity, doubt, or fear. But you can't let that stop you from moving forward.
This is easier said than done, and some situations seem impossible to get through, but the people who push through adversity are the ones who succeed. You have to look at what you're doing and truly believe in it. You have to believe, with complete sincerity and commitment, that you have the power to make your dreams a reality. And when you reach those moments of adversity, doubt, or fear, you look at what truly matters, block out the things that don't matter, and keep pushing towards the end goal.
BUT YOU HAVE TO HAVE A DETAILED VISION OF WHAT YOU WANT.
Look at what you want to do and say it out loud. Speak it into existence. Write it down and determine a set of long term, mid term, and short term goals that all work together towards your goal. That way when you run into a road block, or don't move as fast as you would like, you at least know where you're going and can make adjustments to your path without losing sight of the end goal.
This detailed and focused mindset of what you want helps and might even be the reason you make it when others don't. You just have to have the patience, persistence, and resilience to never let anything hold you back.