I am a 74-year-old woman and have been with my 73-year-old partner for 30 or so years. Many years ago he had bladder cancer, which is now under control, and before that he had arthritis, which meant he was only comfortable having sex in one position (with no foreplay). I began to dread sex. I thought he was mentally too fragile for it and, as a result, we had hardly any sex for a while. Then our relationship got difficult and he told me he didn’t fancy me any more, that we were old and wrinkled. I don’t know if there is any way back from that.
I am sorry you are facing such difficult and painful challenges. “We’re too old” and “I don’t fancy you any more” are often code phrases for “I have no libido generally”, so try not to take it personally. My guess is that if your partner can be persuaded to seek medical help to restore his sexual interest – which may involve having evaluation for hormone treatment – you may find your erotic connection will improve.