My partner (m) doesn’t want to have SX and rejects me most of the times..I am not sure what to do

I am a woman in my late fourties who is in good health and shape and I love my partner very much but sex is a thing.. he doesn’t want it as much as I do. If lucky it can be once a week but it has to be planned and not much is spontaneous. I feel that I want him more than he wants me although he keeps saying that he wants me too and that he is lucky to have me as a partner.. but I feel a bit unwanted.. any advise?