You're on the right path in terms of trying to nail down the construction of the proportions. However I think all the wireframes and grids are making you to see the face abstractly instead of holistically.
I made an edit, not completely accurate, just a sketch:

Study the volumes and shapes in the face and try to recreate them. Always measure and check the relationships between your strokes. Also I think you could have fun with this pallet. As it stands it's a bit drab, I added a darker color for some added depth, but you could definitely get some knarly light blues/greens in there for the highlights, and some rich purples/oranges/reds. Basically experiment with some hue shifting and more drastic contrast.
Anyway, keep studying and trying to get placement right. Such is the righteous path.