There are people here who lose weight without significant (or any) formal exercise. It's more difficult and takes longer, but basically you just have to adjust your intake downwards, to compensate for the lack of calorie-burning activity.
There are also plenty of people who exercise despite mobility issues. I'm sure someone here can provide you with the link to the "seated exercises" article, it might be something you could consider...
Goal 1 - break 200 (46 pounds lost)**DONE**
Goal 2 - leave obesity behind (BMI 29.9, at 185#) **DONE**
Goal 3 - BMI = Normal (154# or less)
| current weight: 174.0