How do you stop caring so much?

Sometimes I internally struggle with being a parent. This has been more frequent as I often butt heads with my teen. He feels that I focus too much on his school performance and I think he doesn't focus nearly enough. I want him to succeed and do well. He is extremely bright but he just doesn't perform up to his capabilities. We've explored lots of options and tried many things. Nothing seems to be that magic spark to motivate him. I came to the realization earlier this year that I need to just not care so much. Easier said than done.

How do you just not care so much? Is it possible to not worry about your child's future? Did we raise him to just want to have fun all the time and not concern himself with things to come or are we just facing the same thing that all parents face with their teens? I really want peace in our home and am learning more and more to just let things go and try not to hash it out with him. I want to tell him that his choices now might come back to bite him later, but he'll probably just blame it all on us and our parenting when he's older. LOL!?