I am 78 years old and discomforted by enlarging tummy with
passage of time. It presses against my lungs which makes my
Breathing so difficult. Now, my tummy is so enlarged that it's
very very uncomfortable to do day to day activity. My tummy's
X-Rays, CT scan and Ultra sound are clear. There no much fat
either in my abdominal area. I want reduction of tummy.
It seems like you might have excess visceral fat. This is the fat around your intestines. As it increases in volume it pushes against your muscles and causes distension. It also pushes against your diaphragm. The only way to reduce visceral fat is with diet and exercise. You can also consider a bariatric procedure such as a gastric sleeve.
More information is needed to answer your question. Your breathing issues need to be evaluated. If your breathing issues are truly related to the contents of your abdomen pushing on your diaphragm, tightening your abdomen with a tummy tuck which involves tightening of the muscles of the abdomen can make the matters worse by putting more pressure on your diaphragm and other structures inside your abdomen. You need to be evaluated by a board certified plastic surgeon in your area. Check this ASPS website for surgeons in your area.