Way back when...drawing with charcoal or pencil was the most fun for me. Then one day it occurred to me that painting was really as simple as "drawing" with a brush. Here is the actual painting where this "clicked" for me years ago....it is a copy after Ingres...(sorry for the poor digital pix)...
Seriously, if you ever wish to make the transition from feeling comfortable with drawing to feeling comfortable with oil painting....I suggest starting with a limited palette so that color doesn't confuse you. I started with a toned canvas and "drew" (painted) with raw umber thinned with Liquin and added some titanium white at the end.
Because you draw so well and understand the importance of a single source of light, I'd be surprised if you didn't do well with this starter method into oils. I painted like this for quite awhile until I got comfortable with color and thicker paint and found it was a dandy way to begin an underpainting a la the Old Masters.
And I still get nervous when I show my work to anyone. Although I hope I get over it someday (the sooner the better), but I'm not gonna let it stop me
