Account Logging into the wrong MC account

My Normal Minecraft Account Name Is: dotyboyz. i was logged into that account yesterday. when i logged back on today, i noticed my name was different. my account username was This: Fentelle. I didnt change anything in my account, username, or password and i do not know this account or account owner, but it just said that. and my skin is totally changed. I tried relogging into my account and it still said that