YouTube Video Help? (Copyright Infringement)?

In the past 2 days, I uploaded 2 lyrics videos to YouTube. One was for Afterlife by Avenged Sevenfold and the other was Nightmare (also Avenged Sevenfold). At the beginning and end I put the title of the song, the artist, the album (if I knew it), and the sources I used to make the video. On my videos, one has "Matched third party content" next to it. The other has "Blocked in some countries." But it's blocked worldwide now. I knew YouTube has pretty strict terms on copyright, but what can I do to unblock my videos?? Thanks :)