great start so far, I made an edit:

*Removed a lot of the dithering. The main problem is that it gives your skin a strange texture as qunit said. In fact all the dithering makes you look a lot older, as though you have really wrinkly skin.
*Placed it on a more neutral background. This way your face stands out more and the background doesn't get in the way.
*Tweaked the colours a bit.
Also one thing which I didn't really fix was your lines, you should try making them less jaggy, especially around the right side of your chin.