One of my biggest problems is constantly thinking about what could/might/will/won't/should happen in the future. I have expended so many hours of my time worrying over things that haven't even happened yet, and I refuse to simply live in the present, letting myself react to stuff as it occurs.
I fight with myself every day. Stop planning, stop freaking out, stop worrying. It'll be ok. It's not the end of the world. Here's hoping that the honorable Lao Tzu can help me a bit with that.