I agree with seagirl....you just need to create a calorie deficit and that can certainly be accomplished by restricting calories. However, I get the desire to workout. I'm addicted to it, so I would go crazy if I couldn't do it....and I did have a time when I had a huge fracture all the way across my right foot.
Anyway, do you belong to a gym? They have a machine that you can sit at and it's like a bike for your arms. That's one idea. I'm not sure what else you can do. It sounds like you can do running, but not for long periods of time? What about a rowing machine? I have no idea what that would be like on your ankles, but I know it's a great cardio for me. What about doing a pilates mat dvd or class (if you belong to a gym). You can modify it so that you're not on your feet for long. Another great thing for weight loss is resistance training. You could do lots of weight lifting, push ups, pull ups, crunches, etc. and you can do them fast so that your heart rate is elevated...switching up very quickly between sets and attacking different muscle groups. I've heard many people say that doing resistance training is a lot more effective for weight loss than cardio because you're building muscle and the more muscle you have, the more calories you burn at rest. As hard as this is, try to look at this as an opportunity to learn more about what you can do to reach your goals.
I really hope you can figure it out.
First goal: under 180:
Second goal: 175 or below:
Third goal: 168 (no longer overweight):
Fourth goal: 160 or below:
Final goal: 145-155 (not sure if this will ever happen):