We're sorry about the trouble with the CC libraries. Are you facing the issue in all the Adobe apps? Please ensure that the Creative Cloud desktop app is up-to-date, signed in and you have sync enabled in the app.
You can try the steps suggested in the links below.
Mine mysteriously went missing about eight months ago, and just as mysteriously came back six months later. Nothing I tried could get them back, and then , one day, there they were. They actually were still available via the Creative Cloud desktop app, in the "Your Work" tab.