From morbidly obese to fit at 40. Is it possible?!

I'm losing weight and feeling great, but my current lifestyle prevents me from exercising as much as I want. (I have a toddler and a more than full-time job, so my main form of exercise is walking, walking, walking.)

Anyway, have any of you gone from morbidly obese like me (started at 353 in 2006...up and down and up and down...now at 285) to fit and trim after 40 without surgery?

Inspire me. I want to do this!