I feel for you. I had something similar, but not as bad, happen to me. I was hit by a car and my leg was shattered. They pieced it together with plenty of rods and pins, and it took me twice as long to heal. No one was sympathetic. My workplace would not change the job at all to account for the fact that I could not do all I could before. I eventually lost my job, and health care, and have had to work on my situation with out much help from the medical establishment. It has been really frustrating. My leg still hurts and I cannot do running or high impact exercise. I cannot do any job where I need to stand a great deal of the time. I really need to understand and listen to my body and plan my life accordingly.
I think if you look at other options, your outlook might change. For instance, if you could get into medical coding instead of nurses aid, it would be more of a sit down job, and no, you have not blown your education if all you took were prerequisites or beginning classes. What about laboratory technologist-- one of those people who work in test labs and take samples of blood/ urine and do the required tests? That is a job people get with associates degrees.
So I know what it is like not to be able to have full range of movement and also to lose weight.
The great news is that exercise helps weight loss and definitely contributes to things like bone strength, and proper functioning. You can do low impact exercises like weight lifting, and swimming, and bike riding.
You can do it. Nothing is impossible unless you let it be.
