Anxiousness has destroyed many good putts. 

 Many times I have witnessed in my teaching when a player becomes so anxious to see the result of a putt, they turn their head in anticipation only to see the putt not go in.  The second the head turns, the shoulders rotate open causing the putter to veer off-line and often pull the putt left. Watch the professionals especially on those 3 to 5 foot testers, the head remains still well past the point when the ball leaves the putter.

 Place a ball mark just behind the ball on a 4 or 5 foot putt. Practice putting and watch the ball mark as the putter glides through the ball. This will enable you to stabilize your stroke and keep the putter traveling on a true consistent path.