The way I learned to stop turning my head was simply focusing on keeping my eyes locked on my opponent at all times. It's harder than it sounds, as you figured out But when you're in there, just focus on keeping your eyes open and on the other guy. It's a reflex action and it goes away quickly because subconsciously you know what's good for you and what's not.
The most important thing you can do IS learning how to hit without 100% power. Focus on speed and accuracy, put less weight behind your punches. Only use power when necessary in sparring, to force someone to respect you.
When my coach told me I needed to learn to take shots better, he told me to tuck my chin defensively (as an obvious basic tool) and to take the shots on my head and turn my face away inward instead of outward. Slipping, blocking, etc. are all techniques for defense, but when it fails, the last minute decision to turn your head inwards will give you more to work with in absorbing the blow and maintaining visibility instead of flailing your chin/face in the air backing away and leaving yourself exposed with no body behind to take force. Not a bad idea with the young one!
