It is hard to say if you will be able to return to such a physically demanding job. Many haven't. I know it's depressing but I would start thinking about a plan B career wise. You will have a weight restriction for a good while after the surgery and if the outcome is good, I would not risk reversing it by doing a physically demanding job. Maybe a more administrative role in the military if that is an option? I am a dental assistant and will never return to that but I should be able to do front office once I recover. I just had two first rib resections.