Dont start with anatomy start with still life. Put a box on a table and draw it. Then slowly add more to your scene making new drawings. instead of doing 10 completed drawings treat your sketchbook like a notebook, i find that helps, try to do 2 pages a day of quick sketches and observations. Carry it around draw things you see in restaurants and in real life. Example if you go into say a panda express draw the hanging paper lanterns or if you go into a doctors office draw the magazines stacked on a table etc.
A Cartoonist is just a lazy Animator.