Yes, this is an amazing moment in the poem!! I was struck by the same thing and am so glad that John pointed it out and that MaryAnn focused in on it. I love the thin-edge accuracy (I might say tidiness but, especially in the context of this thread, I'm particularly wary to avoid any word that might rev up gender-associated cliches re Dickinson) of the way the syntax cuts both ways here. The way I read it, not only can "struck" be either transitive or intransitive, but if it is transitive, then the ticking is what is struck through, and if it is intransitive, with the speaker as object, then "my ticking through" is an appositive for "struck" -- the speaker is struck and her ticking is also through. And in that case, "through" has a different meaning as well: it means physically pierced if struck is transitive, and temporally over if struck is intransitive. This is really remarkable: THREE different words in the poem, "struck," "ticking," and "through," do grammatical double-duty, and in each case they fit together seamlessly. It's like the Escher painting of the faces and the chalice, a paradox so exactly executed.