Does your doctor have any suggestions for exercises that are okay to try? They'd be your best bet for this kind of advice, since they know the most about your medical situation.
Also keep in mind that the majority of your weight loss progress comes from diet, not exercise. So even if you can't exercise at all, you can still lose weight consistently if you're tracking all of your food and staying in your recommended calorie and nutrient ranges.
Hope that helps,
"You may have a fresh start any moment you choose, for this thing that we call "failure" is not the falling down but the staying down." Mary Pickford