Regarding exercising - it helps if you can find something that you find quite *fun*. Going on a treadmill used to be a punishment for prisoners
What works for me is to do exercise to music - I just go to classes at a local, public gym. Also, you could start off by trying to find a class on a Saturday or Sunday morning. I find its really difficult to drag yourself out again after a hard day at work. At the weeked I feel much more lively.
Finally, try to find a teacher that is motivating without being bullying. If you haven't exercised for ages, you shouldn't be expected to do much high impact work.
I can't stand teachers who nag you to keep jogging all the time - I know when I'm puffed out, and at that point I want to take it down to a walk.
BTW, JungleKitty - a stone is 14lbs