No you cannot change your netid. The numbers at the end are where you fall in line of people with the same initials as you. As far as I know, no one has ever been able to get their netid changed. Maybe they would make an exception for a curse, but probably not.
just read this more carefully... is this true?! i can't believe there are dozens of people in the world with my (embarrassing) initials, let alone in the georgetown network!!! makes me feel a little bit better though