Changing tactics when natural ability is reached?
"I am at the point where I have eliminated everything else in my life except classwork and research projects."

That is likely to be counter-productive. You need to leave room in your life for inspiration to strike, not just perspiration. Go for a walk. Take up a hobby that does not require total concentration. You may be limiting yourself by not allowing enough time for rest and relaxation.

I know I am much more likely to get a creative idea for solving a problem doing something else, rather than staring at it, once I have the background firmly in my mind.