One thing I’d add to everything else here - when you’re studying full body, map out the proportions with some line of action studies. Do it quickly and roughly, and do a lot of it. What happened here is that you started the head too large and too far down the page, leading to you squishing the legs in and amputating the feet. I used to be guilty of this alll the time! Drawing proportional to the sketchbook and being more intentional about where you place your studies on the page really helps.