give me a side of grit

i was reading an article in the latest psychology today about what they call "grit." It was defined as a cross between intrinsic motivation, passion, self-discipline and perseverance. As an example, they used the story of andrew wiles, the guy who solved fermat's last theorem, which was supposedly unsolvable. apparently he drew an income from teaching a couple of classes, but spent the majority of his time from 1984 to 1994 trying to solve this problem. he describes the moment he found the solution:

"... suddenly, totally unexpectedly, I had this incredible revelation. It was the most important moment of my working life. Nothing I ever do again will mean as much ... it was so indescribably beautiful, it was so simple and so elegant, and I just stared in disbelief for twenty minutes, then during the day I walked round the department. I'd keep coming back to my desk to see it was still there – it was still there."

my revelation after reading this article was that i have completely lost my grit. the things that i would push myself to do that benefitted me, like going to the gym and even going to church, i have been blowing off. i still feel a lot of passion for my jobs, but i know that i could feel better and be generally happier if i "just did it," to steal the phrase. i have become tired, energyless and spiritually empty. and that's no way to be.