You have artistic potential. Keep at it. I can see potential in alot of people that others cant sometimes.
I recommend that you draw things using picky measurements, to get a handle on porportons and such.

A human is 8 heads tall
A human male is usually 3 heads wide.
The lip corners meet up with the inner corners of the eyes near the nose's upper half
Ruffly skecth a few faces large, they will probably be off scale and tilted and such at 1st.
Then draw another face, but this time just try to be extra exrta picky as to the portions and facial aspects. Like the face is like 3 eyes long in the eye section...so on and so forth.
Then try some shading.