I had a lot of shortness of breath. In the hospital, they had respiratory therapy all the while I was in the hospital. I also have Asthma. In my case, they brought the stomach up into the thoracic chest cavity where it still competes for space with my heart and lungs. Don't worry. It is something your Dad can get used to. It is a little scarey at first because of being used to having full lung capacity.
I also had a portion of my lung removed that was damaged in radiation. It is not all bad. I, also, wanted the oxygen in the hospital, but the doctors will take it away when necessary. After I got home, I didn't have oxygen and I used a "Combivent" puffer to help with the asthma. I also was on allergy tablets. After a while, I got used to the whole new process and am doing just fine. Your Father will have some apprehensions. That is normal. He will get used to his "new" breathing, and eating, and after several months, he will probably not even think of it any more.
Try to get him to have a good positive attitude and enjoy every day that he can see the sunshine, smell a flower and go fishing or whatever else he enjoys.