I was 35 when I had my first and 38 when I had redo in May. I should have had it done when I was in my early twenties according to my surgeon and GI doctors. Wow, sounds like your doctor may not be up on this surgery. My last surgeon told me he does young children to seniors.
Kinda funny, I was in the Peds wing until last night and a couple of the Peds nurses didn't know hey did Nissens on anyone over 13. They thought it was only for children, because they see so many children getting it done.
Anyway, you are not the first to be told by their surgeon this is only for "older" people or you are too young to have this surgery. Let's see, they do it on infants and senior citizens, I don't think there is an age limit.
Hope all goes well for those heading into surgery, which ever one you choose.