So my saves for the last 5 days have suddenly disappeared and I have no idea why! I play and then save it but when I come to reload the save has disappeared and only the ones from the 6th are there... and I don't seem able to delete them... help!

Check if the saves are present in the save game folder: "Documents\The Witcher 3\gamesaves".

Yes they are but they are not appearing actually in the game... so it's like the game is reading savers from somewhere else or something??

Do a backup of these saves and try to experiment a little. First delete all saves, launch the game without Galaxy (through witcher3.exe file in the game folder), exit the game and copy to the save folder your most recent save. Check if the game sees it after this.