Can I support you by simply saying that it's likely that you've just moved on, as so many others have? I think it's perfectly normal to finish things when canon ends and you've tied up your personal desires for them, told the rest of their story. To fight that and try to write forever and -ever will only make you miserable. What more is there to say about Brian and Justin, anyway? They're happily living ever after, and that's not a bad thing.
Exactly, that's just where I'm at now.