There could be an issue with your "UserSettings.txt" file causing the control problem your encountering. Recreating this file may help resolve your issue.
- Navigate to the Documents folder. (It'll be under favorites in the Finder option)
- Documents\ElderScrollsOnline\Live\
- In the Live folder you will find "UserSettings.txt".
- Create a backup then delete the text file.
- Open the ESO launcher and run a repair.