I found this quote the other day from George Washington Carver and loved it:
compassionate with the aged, sympathetic with the striving and tolerant of the weak and strong.
Because someday in life you will have been all of these.
I hate sounding like an old fart giving you a lecture, but I look at my journey and it continues to be pretty amazing, even with mistakes here and there. The majority of time when I don't get the outcome I was hoping for, if I analyze the situation, almost always I played a role in the outcome. The usual reasons are procrastination, fear of a new direction or not fully analyzing the potential of a new project. However, at this point in my life I've at least learned to get something out of each mistake. Disappointments are incredible learning experiences and help make the next project that much more successful.
So, if now and then you hit the wall and are disappointed in the outcome, take responsibility for the gift you've been given to change your path. We're an amazing industry. All along the way there are people to help you with the challenges. You don't have to do it alone, but you do have to take responsibility for each decision you make and learn from them.