This really resonated w/ me and I wholeheartedly agree:
Knowing exactly what you want to make can often be the largest barrier in your creative journey.
My advice in this situation is to take some time to break the problem up into bite size pieces. Work on little prototypes. Explore each tiny concept and eventually, start to put them together. If you are too focused on the gap between what you envision and what you currently have, you will likely lose faith.