Your avoidance of making her unhappy sounds to me like you have a major hang-up with being the rescuer.
Born fixer here cobra. If I wasn't, the D would have been in 1987.

BTW, did she complain any of the physical discomfort that used to prevent her from having sex? What happen to that objection, or maybe was it just an excuse?
Physical discomforts:

1. Less natural lubrication so we use Astroglide.
2. Post menopausal and no HRT.
3. More UTI's as she got older till we found some steps to reduce/eliminate them.
3. Took tamoxifen for 5 years which depletes natural hormones made in the brain. Fewer hormones lead to poor vaginal lining flexibility. Typically women need more warm up time but have to want to have sex. What is needed is co operation from both partners. The H can't supply all the foreplay and direction to overcome the W lack of interest.
4. BB's basic feeling that once past a certain age almost all women don't like sex and if the H does, he has his priorities in the wrong place.
5. Other physical and mental problems,

So do you see some of the reasons I consider her predicament so carefully and feel some responsibility, to adjust my need for a sexual R with her, but not give up a sexual R all together.

BB is a little like Mrs. Choc. She wants to be chased but isn't interested in the full take down. Me on the other hand, I don't feel like chasing with out doing the takedown.

Several times this difference in sex drive feels like mother nature played tricks on both of us.