Go see your local PGA Professional.

He or she can straighten out your driver.

CHECK GRIP YOUR SHAFT AND YOUR BALL POSITION MAKE SURE YOUR HITTING UP ON THE BALL

have you tried adjusting the position of the club for higher degree usually helps me if not maybe a new shaft something of a higher launch since you are hitting the center  

I got a tip from a guy who got a lesson from Butch Harmon, and he told me to stand literally as far away from the ball as possible. So far that the ball is parallel with the TOE of the driver, not the CENTER. This will enable you to 1. Use your entire body in the swing for added distance; and 2. Stop hitting a pull hook. Also, try not to ground the club. It will feel odd at first, but it really helped my driver. I went from hitting a 220yd slice to easily 250-260 dead straight. Check your grip and swing plane. Place an alignment rod on the ground in line with the teed golf ball. You'll be able to see better whether your clubhead square and is on plane long enough for good contact. You may see that your clubhead is only on plane for a millisecond and closed. I know what you're dealing with. I had hit my driver and irons exceptionally well up until about a week ago. Now I am struggling as well. I'm getting a lesson tomorrow. Maybe if you don't work things out, you should get one, too. Good luck!

it sounds like you might be finishing your swing out of sink.  Your arms are getting ahead of your shoulder turn.   Check to see if your shoulders have released fully at impact, if not then you arms will automatically swing to the left, closing the face and causing your hook.  While this might not work for you, I like to visualize throwing a heavy medicine ball by rotating my shoulders back and forth just like a golf wwing.  Hope this helps a bit.