Have you ever made a total career change, and how did it work out for you?

I have been a trucker most of my adult life, and after getting hurt last winter, I am thinking of trying to do something else.
I have always wanted to operate large equipment, dozers, excaveters, loaders, and so on but I don’t know if I could even get work in that field.
There is a school that offers the training but it is very costly, and the Government would be no help, because there is such a call for truckers ,they would tell me stay where I am.
So have you ever done a complete career change ,and how did it work for you?