Leave what it holds you back, your depression, sadness, angriness, worries.
All of these are obstacles which it is trying to stop us from moving forward. If you want a successful life, you have to believe that life is not all the time sweet, hence it must be there bitterness. Come on, it does make sense, pain exists in our life without pain, we would not be able to taste happiness.
However, enjoy your moments of life, as we live in a limit time, remember that pain will not exist permanently, but it is just a temporary emotions, and it is going to be vainshed. So no worries if you hit the wall, but you have to worry in case of if you hit it and stopped, try always to go beyond the wall a little bit, and make your dream comes truth.
Finally, why you worry when you stop, you should not be. Because if you stop, that’s your limit, and you have done your part.
Note: i know that i said that you need to go beyond the wall, but if you stop, it does not mean you committed a big mistake. I mean! Why not if you still have the ability to go further.