If you feel you need a GAC, you have every right to request one no matter what anyone on this forum says. You don't need to explain yourself here.
Seeing all the trips in your signature, I'm sure you already know how much walking is involved at Disney. If you're not already using one, a wheelchair or ECV certainly would help.
There may have been an additional need not specified on this forum. Or a CM may have had an idea to help we are not aware of here.
I have also seen a CM give a GAC to someone who had stamina or mobility concerns, just trying to help. Sometimes it turns out to be the wrong thing for them, and they should have rented a chair.
I saw something like this happen at Jungle Cruise in DL recently - there was quite a long line in the accessible entrance line (which is just a roped off area to the side of the exit) - (in full sun, though it was March or so, so not too hot) and someone had a GAC that allowed them to use the accessible entrance for whatever reason.
I did not speak to the party, but one man was loud enough that I heard him saying "She cannot stand this long! I have this thing! (waving the GAG around), She is not supposed to have to wait!" I did not see the stamp on the GAC, but the CM reassured the man that the party WAS allowed to be in the accessible line, he really did have to wait in it. He was very upset and made enough noise that the lead came out. Once again, the man was assured he had to wait in either the mainstream or the accessible line at the exit, but those were the only two ways to enter the attraction. When the man again waved around the GAC, a CM pointed out that everyone in the accessible line needed to be there too. Both CMs left him in his place in line at this point.
There was a woman in the party who appeared to be going through chemo (hat, lack of eyebrows, port in her arm under sterile cover).
She would have been MUCH better served by having a wheelchair than whatever GAC she had in that situation. She still would have been in the accessible line, but at least she would have been sitting!
I tell this story for a couple reasons. One is to say that the GAC, on this board and in general conversation, seems to have taken on magical properties, and many guides even make a person feel they MUST have one, no matter what their needs may be.
The second is to point out that while there are different stamps, many GACs result in people waiting in the same line. No GAC "outranks" another, nor does a GAC "outrank" a wheelchair, or vice versa. So if there is a line and a person gets a GAC to avoid a wheelchair, it does not matter if Mickey Mouse himself gave that person the GAC, they are STILL waiting in line. Consider this when deciding whether or not to rent a wheelchair. A GAC usually will not change what happens if a wheelchair meets your needs.