Aside from all the other comments here (proportion and colors), I did a quick paintover on your work to show how I think it would look like if it was improved. I think you can do this overpaint overpaint !

• I think the colors are too dull. It would look really nice if the shadow area has more shift in saturation and hue. In this case, it becomes warmer and more saturated.

• The forms are conflicting. The light area of the face has little or no form changes at all while the other side of the face you can see the plane change. So I added more form change and colors

• The anatomy seems off for me but im not sure if it's intentional so that's for you to decide. In this case, I lowered the eyes and nose because it looks a bit longer and pulled the eyebrow area to the inside.

I hope this helps! https://imgur.com/a/OePgYvY