I think your middle value just needs to be lighter. This would allow you to place it where it needs to be on the light side of the face as well. There should be some separation on the features even on the light side of the statue. Hope this helps
Sorry for the late reply, I try changing the mid tone value to a lighter one like u said and the form are starting to become more comprehensible. Thank you.
No problem on the late reply, WE’ve got drawing to practice, right!! Glad I could help.