Gamertag forcibly changed

So I logged out of my xbox live account on minecraft today, and tried relogging. There were a few issues along the way,but I managed to login. BUT it asked me to make a new gamertag! I already had on, so it does not make any sense! I cant change it to my
original gamertag. It took everything I had in the game with it!

I could only have used one other email, but the same thing happened! I dont have any other emails so I want to know what happened and how to fix this! How do I find out which email is connected with my specific gamertag? Please give me some advice!

:)