Portrait Practice

Thanks for this amazing class. It was really fun. I am looking to improve on anything and everything and want to learn, so please feel free to give opinion about my drawing. I reuploaded after working on the values again. I would appreciate any advice please, especially on values. I really enjoyed shading the portrait this way but don't think I really succeeded. But it was interesting to approach a portrait this way.
Added Joshua's helpful critique of my project. It was really insightful to see my own drawing analyzed in this way and how I should be thinking and what I am missing.