Without failure, we cannot grow. When a child learns to walk, they will fall down hundreds of times, but they never give up or think, “oh, I'll never be able to walk.”
We learn to avoid failure at a later point in life. But if we're unwilling to fail, then we're unwilling to succeed. Pain is part of the process. Often, our pain makes us stronger, more resilient and more grounded.
Most people attempt to numb whatever pain they feel. However, it is much better to embrace the pain and act despite it. Action isn't only the effect of motivation; it's also the cause of it. Get started and do something, anything. If your goal is to simply do something, then any result is success and failure feels unimportant.