I remember i used to turn my head when i threw a punch. bad habit and was hard to break.
Make sure your not in against guys who are way better than you.
sparring is to help you get better.
a sparring partner is there FOR YOU.
your not there to be fodder for some better guy,doing that isn't being tough or showing grit, its dumb and counter productive.
being in with guys who you are scared of doesnt help you at all.
MY suggestion..

stand with your back against the ropes so you cant back up.
have your partner throw low speed soft punches.
practice blocking and covering up as he throws
THEN counter punch,ask HIM where can i counter,,,what do you recommend.
as your confidance builds you become more sure of your ability not to get hit.
REMEMBER an average boxer is IMMPOSSIBLE to hit and hurt when he covers up. remember the "roper doper".... you can only get caught when you open up and throw