It would be much easier if you published the code you have already implemented. as then one could correct only the erroneous parts.
Also: why does it have to be google play musik (uk) if there are scripts for discogs (and other sources)?
Simply because I've noticed that, with Google, for the majority of the music I listen to they do not put the featuring artist in brackets next to the title. I've come to learn that it's fine using cloud-based services like iTunes Match and Amazon Cloud Player, but for Google the track then uploads instead of matches when I try to upload to their cloud. If I then make my tags exactly the same as listed on the Google store the original track which uploaded then matches, which makes me believe Google does not just take an acoustic fingerprint of the track, ID3 tags also play an important roll in the scan-and-match process. Many, many tests have confirmed this for me.