young boy portrait - part two.

So i spent a few hours one evening working on my project picture, and I'm quite happy {and surprised} to say that it's going pretty well. There are some things that I still need to work on, and the face shape still isn't quite right {very very very difficult to get that similar to the picture, especially because my image is a larger scale of it.} Here's how it looks right now, compared to the original.

As you can see, I shaded the eyes a bit more and defined more of the hair. The nose and mouth and lines are also more defined. Next time I'm going to work on the hair the most, as well as fixing up some details. I also think that the space between the nose and mouth is a little less than it should be, so I might very possibly change that next time :)
I have found that I enjoy working on this project, but once I have drawn for an hour or two, I need to stop before I make unnecessary changes and get frustrated!
Any suggestions?