I have double of everything in my music library.

How do I get rid of the duplicate songs?

There is no easy way.
TuneUp does it but its not free.

File->Display Duplicates->Select All -> Delete

Is select all->delete not going to delete my whole library?

Try this

Deleting Duplicates iTunes

There is a find duplicates feature iTunes. If that don’t work you could try using the iTunes match service which is great if you also want to back up your entire collection to the cloud. It will identify all duplicates.

hahaha I’ve got duplicates, some of mine are 4/5 duplicates, half songs, no album covers, no track names….