I came up with Nomyster because. My brother stole MrNomymine it was originally my account. But I had Nomymine but it was too boring. So I was thinking Monster and Nomymine so thus came. Ⓝⓞⓜⓨⓢⓣⓔⓡ
Try deleting all your mc files. Force update. (Make sure you use your username and password or the update wont work) Then all your files what you did in Minecraft will be deleted like your worlds and server saves but it will be fixed.