Play music was shut down long enough ago that you may well have sorted something out, but in case you or anyone else reading hasn’t, then you may well still be able to download your full music library.

Google takeout let’s you download your library, unfortunately it just gives you a bunch of zip files filled with random unlabelled files. You can then use something like Picard to sort out all the file names and metadata. It’s a bit of a faff, but it gets the job done.