Windows Media Player messed up my library?

A few months ago, windows media player messed up my library. It retitled a lot of songs, put them in albums of other bands, changed some album covers to a different album's cover, etc. So basically it messed with every type of information of the songs. They have similarities, though, like in my Green Day album Nimrod, there were a lot of songs from Viva la Vida from Coldplay (the coldplay songs were retitled to the exact green day songs, like the song Viva la Vida was retitled to Reject, but the Reject song by green day is also in the album still). So yeah, it just messed with all the songs and stuff. I'd say my library is only 70% intact right now. I tried copying all of my music files, pasting them in a new location, deleting the old location, and adding the new location to windows media players list of places to take songs from. Didn't work, it just put them up the wrong way again. I just tried restoring the library, and at first I thought it was working because one Green Day album was coming out right, but then a few Coldplay songs were retitled to some of the songs in that Green Day album but they were labeled as a different album. With this one, two Coldplay songs were retitled to two songs in 39/smooth (green day), under the album title 39/smooth, while the actual green day songs from that album are under the album name 1,039/smoothed out slappy hours. So yeah, I don't get what's going on here. It's just jumbling little portions of albums and bands and titles and artwork and everything... How could it be changing the information on it's own like that? My library used to be completely fine.