You're focusing on the nose way too much; first, refine and establish the basic shape of the head, then fit the features onto that shape. Try reducing the vertical height of the face, seeing as it's a tad too long right now, and bring the chin inward a little. Tilt the ear back some -- it's a lot less vertically-aligned than commonly thought -- and drop it down a little.
Fun fact: you can tell a lot about a person's thoughts and concerns about their face and appearance through self-portraits. People tend to exaggerate or 'set off' features that they are self-conscious or proud about (

). As for you, I can tell that you are focused on your nose, and are making it a little more prominent than it actually is. We naturally see noses as smaller, and when we sit down and draw (erm...pixel) a realistic face, it's a real wake-up call about how big noses really are.

A very good start though! I like your palette choices -- very dynamic, very 'fleshy'.
