So Ive been able to resolve the issue!!!
After the Android 6.0 "Marshmallow" update (2015), Samsung changed USB mass storage mode to
MTP mode but this new mode doesnt work in the exact same way, so it appears that the only way to sync your iTunes music & vids to Android using DoubleTwist is to upgrade to 'AirSync', but it will cost you £5.99!!
But I was able to find a free software called
'Sync iTunes to android - Free' which lets you wirelessly sync your iTunes to Android! They also have a paid version,
'Sync iTunes to Android – Pro' (£2.39) which allows you to transfer more then 100 songs in each playlist (and apparently removes all ads)
It transferred all of my playlists like for like within minutes, but it did jumble up the order within the actual playlist... But its free so I cant complain too much hahaha
EDIT: All the playlists have also transferred to Google Play Music where you can re order the songs in each playlist. Your welcome!!!