At first, I was going to say not to worry about it, because it'll get deleted automatically after some time -- but I see the issue you are in... it is currently tied to your current misspelled profile, so it won't let you rename your profile.
There should be a delete option available for gedcoms before they are imported. But its been so long, that I don't remember how to get there.
Its also possible that because your gedcom was so large, that it got stuck, and never got to the compare phase (which is where the delete option is, if I recall correctly).
Best option then, is to email info@wikitree.com and ask them to take care of it for you.