Dunno your situation or goals or whatever, but I had the same feeling with a lot of my creative projects. I wanted to have written a novel or made a game or whatever the case may was. Currently I've found enjoyment in writing scripts and shorter form things, and doodling modest sized things rather than trying to make some grand work of art.
Just took a while of trying out different types of creativity to find the ones that I enjoy doing as much as I enjoy reaching the "have done" step. Best of luck to you.