Yes you did.

And if you paint it yourself the key is prep. Rust is a living thing under the paint and just painting over it, it will keep growing. So I think you'll need to take the fork off and get all the rust off. Probably means chemical paint stripper which also will let you check for even more rust. Then once clean, rust free and thuroughly dry just repaint.

Steel's a lifetime bike but rust is its one mortal enemy.