Partner in 40s no libido?

Need advice my partner says he just has no libido anymore and never evene wants to try having sex because he is.afraid he cant get it up or cant finish. He is only 46. He keeps saying it.is age but 46 isnt that old. I am 35 and my sex drive is so.high now so it is really putting a strain on us. I am trying to be sensitive but i dont know what to suggest to him to help. Any advice?