What does "off the rails" really mean?

Sitting listening to Icky Thump with a cold cappuccino from Bridgehead trying to finish an accounting assignment I realize my life has become slightly derailed somewhere along the way. I don't know where this happened and I don't know exactly when I found out, but there are a few indicators to this crisis (I'm not calling it that, I'm just using someone else's description....so I am using it). The first would be the random thoughts (see previous sentence). The second would be my ever-growing (aka never shrinking) to-do list both at work and at home. The third to infinite (minus the in-between points I care not to write at the moment) would be my chaotic inner feelings. Hope? Despair? Fear? Anxiety?
Quite frankly, I feel like a top that has been spun.
So...what will I do?? I first will finish listening to this album as I finish this assignment. Tomorrow I will go to work. Friday night I have no idea about. The worse thing is I will spend more time figuring out what I want to do after work than actually doing anything. Metric is playing tomorrow at Bluesfest. I think I want to dance.