Steph,
I am happy for you. You have done well preparing for the surgery. Hope you get through the process quickly. Losing the initial weight will be good for your recovery.
I did a similar thing. Started doing an aerobic kickboxing class three nights a week and walking 2 nights. It was too much for my schedule. I know if I am moving, it is good. So for now, I am finishing my first month of kickboxing and since surgery is in 2 days and a wake up, I won't resume until 4 weeks post op or so. But walking until then.
Good luck. We can push each other. ; )