You just have to do your creative work, whatever that is for you. Failure or success are matters to be assessed much, much later, once the work is done and behind you. Most likely there will be elements that you ultimately decide have failed and elements that have succeeded, but you’ll learn a lot from all of it. And these lessons will be incorporated into what you’ll do in the future.
I recently came across an interview with Leonard Cohen where he touched upon the necessity of sticking with whatever you are doing, taking it as far as you can. The creative process is the sandbox you play in; it’s where you explore and try things, where you find your way through fits and starts. To get out of the brush and find a more hospitable place you have to start walking and clearing the path.
“Before I can discard the verse, I have to write it… It’s just as hard to write a bad verse as a good verse. I can’t discard a verse before it is written because it is the writing of the verse that produces whatever delights or interests or facets that are going to catch the light. The cutting of the gem has to be finished before you can see whether it shines.”
– Leonard Cohen