Been there and done that! I entered an image into a contest once and spent over a week working on it but I couldn't ever get it the way I saw it in my head. So I scrapped it and did something else which flowed much better.  I don't consider it a waste of time though. Even when something doesn't turn out the way I expected, I still learned stuff while trying.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi