I have to take a break every now and again. I do models for gaming and a lot of dxf work. that find myself so frustrated that I have to shut off the system, and go have a beer at a bar. talk to a few people and eat some food. I find that it helps a lot. everybody loses their creative ability every now and then. given a couple days away from it in your mind will process some more. good luck and have a nice day famine