Start small, celebrate often! Just one baby step at a time!
I got this idea from a Spark Group about 6 months ago: every single day put one dollar into an envelope. It can go towards anything you like. You can make it ongoing or you can do it for a prescribed amount of time. If you can afford it, put more. If you can't put less. But just do it every day.
Whatever it is you want in life, the outcome is determined in a large part by your attitude toward it and about it. Yes, losing weight is difficult and sometimes long, but so was becomoing overweight a long process. When you think you just can't anymore, read the success stories of those who did.