...and I don't know how!

I really want some help guys! I have been drawing for around fifteen years and yet I still have the art style of a 13 year old! For some reason I just cant get over this hurdle. I have all the best tools and programs so I am all set items wise but I NEED... something.

I honestly don't know what it is. Being better at anatomy is the biggest hurdle I think but it is closely followed by colouring. Does anyone have any tutorials or videos you think would help me?

Thank you for any help you can give!

~Redd