feeling stuck.

i guess just asking for advice? ive been doing digital art (and some traditional) for a few years now (first an ipad, now a drawing pad connected to my computer) but i feel like ive plateaued in the last year. looking at my art from a bit over a year ago, i feel like i havent improved much, specifically in shading and detail. my style is very cartoony so ive struggled to apply tips i find online for realism to my own art and i just cant seem to understand how to add details like creases in clothes or shading.

the first 4 images are all fairly recent, the 5th is from about 7 months ago and the last 2 are both from this time last year. aside from some minor changes, i feel like my art hasnt really improved and in terms of shading has probably gotten worse because at this point ive just given up on it and dont often try to shade my drawings anymore.

how can i improve?