Help needed - feeling at top of backswing...

Ive been struggling with my game recently but thanks to a few posters here they correctly identified that i was swinging over the top a little and since ive started to swing a little from the inside again the results have been great so much so that today i shot -1 on the back 9 of my local course and beat my best ever score by 4 shots! (Shot a 74 - not bad for someone thats only started playing again for 6 months)

However every now and again i have the feeling on the backswing that my club head is open, today it happened 5 or 6 times but each time i was able to stop my swing at the top of the backswing and start again. Im not exactly sure what the problem is all i can explain it as the feeling at the top of the backswing that my wrist may have broken down a little and the club is open if i completeted the swing id have to work very hard or else id slice the ball, luckily i can sense this feeling early enough to bail out of the swing and start again.

Ideally though id like to identify whats happening to produce this feeling. Most of the time it feels great in that position and its almost as if i know once the clubs set that im going to hit a good shot, similarly when it goes "wrong" i know unless i work hard through impact my club face is going to be wide open.

Has anyone else had this feeling on the backswing? Im hoping someone can highlight whats creating this feeling so i can stop it happening.