@RebekahVeuger, hoping I'm wrong, too :-)
It's been a while, and of course those errors are not in the new KnowledgeBase, but do you know how to look for those dreaded ""N Records"" in the CU_Address table? If you have a failed sync you will get those records and the only way to remove them is to run the Rebuild CRM utility. That will repopulate the CU tables based on the mirror tables.
Before doing that, though, you probably want to look at the CRM Activity Log to see if there any errors indicating SQL communication problems, etc.