Whenever discouragement set in, dont decrease your goal or dream, rather you increase the effort in order to achieve what you already set out for.
The problem is not that your goal is too big to be realized, it is just that nothing worthwhile comes easy, you required to go through the process of hardwork anf patience in order to get to your desired destination.
So when you hit a roadblock, dont give up, just keep pushing and increase your effort and over time you will get to a place where you will scream, i have made it, until then keep on keeping on.
Cheers to your greatness.