Is there any way I can change my username?

I'm sorry there isn't. You're not the only one who hates your nom d’utilisateur though, at least Jeffersonian is simple to remember and can be shortened to Jeff which is kind of cute (wait no, *sobs* Jeff Goldblum ruined my favori montrer so I hate the name Jeff), try to find some positive things about your name eventhough toi don't like it anymore. Oh and don't rant like me, you're supposed to find that oddly placed commentaire funny (It's probably not though) so you'll forget about how much toi dislike your username.