Wow! 4 dress sizes Venecia, that's some serious downsizing - congratulations
I first started walking and then jogging to try to counteract the imsomnia I had when I quit. It has mostly worked too. Losing a few pounds was a bonus but it must be good for me as I have a sedentary job.
Luckily I have the Regents Canal nearby which is not only flat but traffic free, apart from pushbikes