Two of my stepbrothers have FASD. I don't want to scare you, and I don't know what you've looked up, but they've both got some problems. One of them is stuck in the mind of a 13 year old despite being 37. He's actually funny to hang out with, but you get tired of him very quickly. He gets a lot of state help with money, so he's able to hold a part time job and have an apartment. My stepfather actually adopted him when he was young and controls his finances. He could've just dropped him when he was 18, but he's been really good to him.
The other one, his older brother is far worse. His mind is somemwhere around the same level, but he's in and out of jail all the time. Mostly stealing and identity theft. A real piece of shit.
I do think most of that comes from environment though. The older brother was raised in an institution for reasons I don't really want to say.
Good luck man, you're doing God's work.