Your account is almost brand new. Just go ahead and create a new account, there is no other practical way to change your username, exceptions can be made though.
I do not advise this way, creating new account is not following the protocol that we have here on our forum. If you don't like your name, you don't have way to change it, you need to accept it and learn how to like it. Or else, why don't you try to donate for the development of this forum? I myself doesn't like my name but I learned how to like it, right now you can see me, still contributing for the development of our platform.