66 years old, 5'2", weigh 100 lbs. Am I too old for a tummy tuck?

I am 66 years old, 5'2", weigh 100 lbs. I work out five days a week, I'm on natural hormone replacement ,therapy but have loose skin above my c-section, had one birth when I was 41. I am wondering if I am too old to have a tummy tuck?? I went for a consult and the doctor said he doesn't operate on women my age because he can't guarantee elasticity of the skin. He said I have diastasis and umbilical hernia and all the workout in the world will not make me narrower. I am in great shape everywhere else. HI spent my 40s and 50s caring for my son and now I feel great, but am self conscious about my middle. Am I wasting my time? I take no medications, very healthy.