Had to change AOL login to apple login & now can't authorize/play previously purchased music!!

I have bought a ton of music from itunes under an aol (login) account. Recently, Apple prompted me to change my aol ID to a mac ID instead. All my information stayed the same and it was just the actual login name that changed. However, now I can NOT play any of the songs that I bought over the years because they are all under my old aol login. When I try to authorize it by putting in the password, it says that login no longer exists (because it was updated to a new login name). And when I put the new name in, it still wont play the song (whole authorization process starts again). HELP!