Hate to hear it Dave. Try something drastic to change the feel. Replace the grip with a significantly different size, maybe even change your hands (claw, left low, etc.). I have a buddy that even went left handed on putts. Good luck!

My old pro used to tell me to concentrate on my trail (right hand for a righty) hand when I started doing this. It always seemed to fix things.

Practice with just using your lead (left) hand only. Just don't alter your wrist position (cupping). Put an alignment stick under your arm pits to rotate only your shoulders.
Seek professional advice.

Have you ever been on a sam putt lab? IF not I would recommend it as it can show you what is going on.

I feel for you and understand what you are going through. I started doing a couple of drills that helped me.
1) I putt on a 4 foot metal ruler. Lay the ruler on the floor and start with 1 foot putts and putt until the ball rolls on the ruler through the end of the ruler. Keep moving back as you get you get better at rolling the ball straight off of your putter face.

2) I also use the putting trainer Puttout.

go back to basics. check ball position and your alignment (especially the alignment of your shoulders). i also think those putting mirrors are excellent to check fundamentals and eye position as well.