There you go. That tells you all you need. Only one thing causes saddle sores and pain on a well-fitting saddle.... damaged tissue. Normally something suffered by new riders. Hand numbness... only one cause... weight on your hands.

Golfers spend huge hours (often with a coach) practicing form. Form... is essential to golf. Correct posture and proper form is also important to painless cycling. The bike has 3 contact points. Bars, saddle, and pedals. Your weight should be distributed, and elbows bent. I'd guess as your legs have strengthened... you've discarded proper form and plopped your weight on the old comfy saddle, and leaned to the bars.... letting your strong legs carry the load. Get a new (different) saddle (temporarily) ... and stay OFF it. Bend at the elbows.... always. You'll be enjoying your old fit in no time.