Your neck should never have been involved in supporting the weight of a guitar. You should have been using the strap to place the weight of the instrument across your shoulders ~ mostly on the left shoulder (assuming you play right-handed), but with at least some of the weight distributed across your upper back.

I've been playing for over 40 years, so we're probably in about the same age group. I'm 5'11", 200 pounds, and male, which means we're NOT the same size/strength as each other, so I realize my experience is only partially relevant.

I'll sit down to "practice" (i.e., play at home), but invariably stand up to perform, certainly to sing, and so have always relied on the very common, normal, guitar strap to hold my instrument up.

My strap runs from the tail/bottom of the box to the headstock, which some people apparently consider less than stylish ~ they reportedly prefer to attach the upper end of the strap to the bottom end of the neck where it meets the body, not to the headstock. I wonder if such an arrangement might put greater weight/strain on the player's neck that the wider distribution of weight afforded by the less fashionable tail-to-headstock configuration.

Well, you have apparently found a solution that works for you. My observations might be of greater interest to others reading this thread than to you, leenia ;^)

PS: How heavy is that gitfiddle of yours, anyway? Are you playing a Teleacaster or some such solidbody electric? They're pretty heavy. Your standard acoustic guitar is really mostly air, not that heavy at all. Installing an under-saddle pickup only adds an ounce or two to the burden...