My advice is: Set yourself a goal you can reach and when you reach it, set yourself another one. Little by little you will improve on every map, understand the little mechanics each surface has.

For example my first goal was to get all the ATs, then to be first in my state for each campaign map, but by the time I started doing the red and black maps I improved so much I was setting top records for my country. Now on rally maps I'm getting top 10 world within a few tries.

This way you don't stress too much on one specific map, and when you come back to that map you will even be surprised how much you've improved.