/ic/ - Artwork/Critique

I've picked up on a loop in my daily practice and it's bothering me.

>Open sketchbook
>Do 2-3+ pages of fundamental X, looks objectively decent
>Do 2-3+ pages of fundamental Y, looks objectively decent
>Draw from imagination and it ranges from abstract to mediocre
>~3 Hours pass
>Wonder where I went wrong, mildly frustrated
>Think about where I want to be
>Repeat the next day

What's my problem? How can I change my approach for better results?
>inb4 draw more
Explain to the best of your ability.