mpshube,

You should not be concerned about further injury. There is no way to know if you caused injury. Even if you could know, it would not change anything. Just stay the course of quiet rest and moderated activity.

You may experience an increase in symptoms. As I said, just keep on course and you should be OK. You may want to ice your neck. A top hit like that can compress the neck and would warrant being careful with your neck. Be easy and ice it.

My best to you.