If your doctor has give you the okay to exercise, you might try some chair aerobics. Coach Nicole has a couple of short aerobics workouts that can be done while sitting in a chair. www.sparkpeople.com/resource/videos-detail
If you go to YOUTUBE and search on chair workouts, you'll find lots of other workouts you could try. Work your upper body muscles while your foot heals. And continue to do your upper body and core workouts too.
As long as you are mindful of what you eat, you will not gain weight. When it comes to weight loss or even weight gain, what matters most is what we eat. Good nutrition is what takes the weight off and keeps it off. Exercise is what keeps our bodies fit and healthy.