Hi Huy,
while there is nothing wrong with your painting so far (I love the pale complexion!), it is the bust itself that bothers me a little!!!
The bust shows George C. Scott in his Patton rôle, but Scott wasn't that old and wrinkled when he played it, and while his acting performance was exemplary and brilliant, he looked nothing like George S. Patton III. (which he readily admitted.)
So, when I look at this bust....I have my troubles "finding" anybody!
Maybe it's the art in it...and I'm simply getting old and can't see it!!
Cheers
Romain