Good afternoon lovelylinda,
I understand what you want to do, the cancellation of your current nickname takes some time to be completed, as for the registration email I am not sure if it will be cancelled along with your nickname, and thus be able to use it for a new registration this time with the desired name.
The best thing to do is to contact our team of moderators through the following contact:

https://games.flyordie.com/s/reportAbuse.html?portal=flyordie_com&lang=en

Good luck and regards
Dav7d