I am always up for some collaboration for fun projects too. I would be up for working on some things with you, if you feel you may need a push to come up with something new. I can feel your energy. You are feeling a bit lost. I can tell because you are unsure of the art path you may want to take. Everything sounds kind of exciting but your not sure if that what you want to do. 2D game art? Tattoos? Illustration? I have seen you get excited by a lot of things.
Going back through the lessons I think would be a good idea. Maybe take them in subjects, instead of terms. like go back and do all the stuff on perspective and environment, then maybe just do anatomy, then zbrush only, etc.
I am entering into a Legend of Zelda art challenge this month, and you know I am always doing outside courses mixed in with my stuff here at ArtSchool. You are always welcome to join me on those projects. Just hit me up and ask me what outside stuff I am doing, and if it sounds fun, I can fill you in on details.