Check the task manager for Tiworker.exe. If that is taking up CPU, just let it go.
As McKnife says: 2016 is slow on applying updates.
If you don't see tiworker.exe using CPU cycles and it's just hung, stop the Windows Update service and then re-check for updates. When you do this, it should restart the service and start the process over again.
By also each time, not to choose so many updates to apply.