This is almost universal any time anybody begins magical practice, and it's the first great test you face in your quest to become a mage. I know the feeling well -- I went through the same thing at the beginning of my own studies. The source of those impulses is the Watcher on the Threshold, the personified energies holding you in ordinary material existence, as much for your own safety as anything else. You can overcome them simply by maintaining your practices no matter what -- and that's the only way you can overcome them. As I said, this is your first great test; if you want to proceed on the Path, you must keep on doing the practices and not let yourself be distracted or discouraged by the Watcher.