Nice portrait! There's just a few things that I would point out.
Be very careful in your initial drawing that you line up the proportions correctly. The nose and mouth are lined up, but the eyes are off center. One way to easily see this particular mistake is to draw light lines from the outside corners of the eyes to the center of the nose, then see if a line is significantly longer. Also, try to be more observant of light and shadow, as adding a few highlights or shadows will go a long ways to adding to the illusion of depth.
Aside from that I'd just say work on your details, and keep observing and drawing.
Thank you for the honest critique. ^^ People really aren't my speciality. X_X Though I did buy a ruler and used it for this piece in order to try and get the proportions correctly. Plus I used charcoal and pastels, two mediums I'm not too familiar with. At first, I wanted to paint a portrait using acrylics, but then this sketch sort of turned into the final product, I guess. hahaha
Yeah dude, people can be really hard. If you're off by even a centimeter or two, you could completely ruin a portrait. But good for you for taking the time to thoroughly measure. I'm not sure what guidelines you used, but here's a generic way to measure that's pretty effective if you're struggling at all.
Maybe, I can't tell in the reference photo I used. And yes pastel is something I'm not very used to using, I mainly using mediums such as acrylic for color. I'm also not very good with charcoal. In general, you could say, chalk-like mediums.