Its mostly a matter of lack of direction early on (i didnt really start to improve big time until maybe february 2018) and having to split my focus while studying along several different mediums. Like only recently do i feel like my figures are alright, but my painting technique is still bad. I also need to improve on landscapes, animation, and composition.
5-8 hours is more of a goal to meet than something that i already do. Of course having a day job interferes with it. If i dont live with my goal in mind then if i ever make my hobby a career ill never be able to keep up. In the 5-8 hours i include any doodles i make in the notebook i carry around. It helps to pad it out a bit. Dont discount doodling because it helps to record any ideas that may come up in your normal daily life.
Not every drawing is gonna be gold too. Some are just better than others due to some universal feng shui i have yet to get a feel for.
Pic was done a month later from the one you showed. December 2017
My goal is less having absolute artistic excellence and more having undeniable skill that i can utilize when creating mildly unsavory or questionable content.