Greetings: I have a remarkably similar problem. CClibrary is slowing my macOS High Sierra. I'm being lazy here because I'm frustrated... I Love Adobe Flash Player because I Love playing time wasting games, such as MyVegas. I Love Photo Shop. But I don't use "the cloud" for anything much that I am aware of, aside from games and Photoshop.
So, CCLibrary is making my computer running 10.13.3 takes like 10 to 15 minutes of spinning pinwheel to switch between tabs. So one tab is ebay with no search criteria. And the next tab is ebay with search criteria. And wow, 10 to 15 minutes later, the tab with search criteria is still not opening. It is not just hitting the CPU, CClibrary is using a lot of memory and disc and not so much cpu but is the best my mac can do for the search on ebay: