@AntiqueGuitars: The contents of /etc/apt/sources.list.d/insync.list shows that the Insync repo was disabled when updating to Trusty. Please remove the # at the start to enable the repo again so you can install insync-nautilus.
For the issue of files from your PC not being synced, please send your logs to support@insynchq.com for investigation: How to find the log files.