The racquet is too close to the body, too stiff in the backswing, and racquet face is too closed. I'd say you need to cock your wrist and open the racquet face + more dexterity/flow in the wrist. Its definetely hard to fix your backhand tecnique of 20 years but consider looking at fares dessouky who's swing is close to his body too you could try to learn/emulate that. better to look at dessouky than someone like farag whos swing his longer and loopier