Headache during squat

[maxitis]

Hello,

Last week i tried to keep my head down during squat.(Difficult because of the mirror in front of the rack).
It wasn't from the first training day, i think it was on the second or third day that i got an acute pain in the head, approximately on the place where the neck connects to the head.
The pain come at the final reps and it could take 30 mins to disappear.(i was laying down).
After that, i get that pain from even doing pull ups.(again on the final reps).
I rested for a week but the pain come back when i tried today to do pull ups.

Here is the video of the session where the problems begin:
https://www.youtube.com/watch?v=rQ2CNIAg6vk 100 @ 70kg

I think is obvious that the problem is on the ascending part of the move where the inertia or my idiotness is resisting some weight with my head.

So, would like to ask what line of actions i should take so as i will resolve the problem and also prevent it for the future.

Thank you.

[TinyArnold]

Lead with your hips, not your chest.