#I'm 4'11" and I've never been average height for an AFAB person in all of human history

[marzipanandminutiae]

Yknow sometimes I think about collecting more antique clothing to wear but then I remember that I'm 5'10" and ladies weren't that tall back then

Oh, they were! Just fewer of them (throughout the 18th and 19th centuries, average height fluctuated as low as 2" below the modern average, or as close to it as no difference at all). And their clothing is less likely to survive, because larger or longer garments could be more easily cut down to make clothing for smaller relatives and/or children. That's called "survivorship bias," and in clothing history, it's the reason small clothes tend to be overrepresented in museums. There are other factors, like formal milestones for which clothing might be a significant memento happening mostly early in life, when you're at your smallest adult size, but that's the most relevant one to your situation.

Also, don't feel too bad- a lot of antique clothing isn't wearable for not immediately obvious reasons. From concerns about silk "shattering," a form of damage that's literally unrepairable, to iron mordants in black dye making black garments fall apart faster over time, your best bet re: wearing antiques is to stick to things like undergarments and maybe blouses and outerwear. Sad but true.