No Laura, that doesn't sound good at all, if you are thinking of hurting yourself! Now I have always listened to the same song over and over without ever getting bored with it. As vjdragonfly says, very possibly it IS manic, except it's something that I have always done, and it's hurting nobody. If the remedy to that is for me to consume more meds, and turn into a mindless zombie to subdue myself, then that's a no-go for me.
But with the hurting business, that's not a good sign for you. If you continue thinking like that, I'd contact my doctor, as you might just put your thoughts into actions if it's not kept in check. And I guess if the constant DVD watching is a new occurance, something which you have not always done, then something's up. Check it out with the doc.