Hmm, I used to think like that: I was never happy with the results I got, every time I draw a map I had to erase it because I didn't like its shape, took me hours (even days) to get a nice result. For the style was the same thing, I wanted to get something like Diamond's or Ramah's style, but all I got was a five year old child sketch .

I started drawing random maps (so that I wouldn't get that worried about the shape) to try new styles and improve my skills, and I can say it worked - and it is still working. My mapping skills have grown a lot, but of course I'm not even close to "perfection".

All I can suggest is that you should maybe stop for a while your project, at least the map part, and start drawing maps just to improve skills, get into Lite Challenges. This worked out for me on the map style "side of the coin", on the other side, the landmass, it also helped a bit, but what helps more for me is to look at others people maps and get inspired by them - sometimes you have just to forget the thing you have been trying to solve, to get the right answer.

Good luck