Sam, I was thinking about your dilemma. I think a big problem with what you are experiencing is your need to top yourself... to be bigger and better with each image. It comes to a point where you just can't keep it going and you burn out (points to myself). There was a point where I would do some graphics as a favour to friends or their friends. At first it was fun, and then it became laborous because each time I made something, I wanted it to be even better than the last, and I felt I had a "standard" to live up to. Soon I was spending sometimes spending 20 hours or more working on one graphic for someone. It got to a point where I just couldn't keep up that pace. I finally came to realize that art is art and it's meant to be spontaneous and fun, not plotted out and agonized over. Unfortunately I didn't come to that realization until I had already burned myself out of creativity. Stop trying to best yourself. Just be creative and make things that appeal to YOU, and not things that top earlier projects. The only one judging you is you.

"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