My server (or my account) just died suddenly... or sth

Hello, I'm back.
Okay.. so, I will explain what happened without any stories, because supporter Julian is rude.
My friends and I didn't go to the server for some time idk maybe month but i don't remember exactly how long. When I wanted to come back to my server I couldn't because when I logged in via facebook, It logged me in but told me to register and enter my username, so I entered the same nickname as I had on the server, but it popped up that this username is taken and idk how to log in now. I think my account has been converted to another?? from what i think idk. : /

I want to recover the server and map I had, because we had a lot of fun building it all with my friends.

Also.. Julian can u not closing this thread, because u just too lazy to read? smh
And I'm sad...