I didn't quit drawing, just got frustrated that I can't get the thing right...
I believed that using 3D as assistance will improve my drawing, but I never get my model to look good in every angle, and I checked out some other models from the internet. It might look fine as a model, but it just look terrible when traced to be linework. This really get me nearly mad and I've been stuck at an idea that I'm unable to draw for days.
Don't know if I've pushed myself to hard, or I just don't have a talent for it.
Anyway I won't quit, maybe I need some time to calm down.