Re: "I found out when we were barely in the age of the internet we know today, but I wonder if there are some older members that can talk about how they found out they weren't alone."
"internet we know today" brings up an interesting twist to the main question ("when did you find out you were not the only one . . .").
In the 60's & 70's, the internet was a new way of communicating information, used by university professors, defense contractors, and uber geeks. Basically zero AB/DL content. You had to walk into the right adult book store and find a cryptic ad in a fetish magazine, and then you might be able to join a (snail mail) mailing list that had ABDL content.
As in "printed on paper" content!! (For you young'uns- "printing on paper" was an archaic form of communication- content permanently inked onto sheets of pressed white cellulose!!).
The 80's brought the "World Wide Web" (e.g. anything
www.---). The Internet was now somewhat accessible for the average person. Special interest sites come into existence. The first and biggest is DPF.
I found DPF through a magazine- a tiny alternative Magazine (forget the name). I saw an ad for back issues, and there was a cover that included a headline- someting along the lines of "Sausalito's Diaper Cult" (Sausalito is a S.F. Bay Area town, where the founder of DPF was located". Of course, I ordered the back issue!!
Somewhere along the line, I became aware that this organization had established a presence on this mysterious
www-thing, and I visited it, and pretty damn quick found an iconic pic ("TB Mark"/ "The ABZ")- a TB, about my age, on a floral print bedspread, wearing a thick disposable diaper, and sucking on a baby bottle. It was everything I ever wanted to be, a and someone took s picture of it and shared it.
That was the moment for me!