I think that Sandy has good advice. Take it one day at a time. Start with walking a block or two, rest a day, then repeat and maybe add a block. Rest and repeat a day or so later.
I was also very active prior to SRS, but not at your level. I was going nuts with the dramatic change in activity, though. I started logging my day's activities on the calender. I noticed that some days were high energy days, and were usually followed by exhaustion. As the weeks went by, I noticed that I stopped filling out the calender, and had naturally resumed a normal life.
I would also trying bike riding when you think your bottom can handle it. It is less taxing than running, I found.
Now might be a good time to get some housework or shopping done. You'll get some exercise, have a clean house and maybe a nice pair of new shoes!