You remind me of a story! Years ago, a couple years before I started writing on Medium, I began a friendship with an 18 year old gay guy who had a ton of questions about how to come out and how to live authentically as a gay man. Some people will know who I'm talking about and that he eventually became an occasional Medium writer himself. I'll take a second to boast, because I'm proud of him, that he is now a very successful young professional.
Anyhoo ... In a bit of a panic one day he asked me confidentially if I could reassure him about something. I'm really not attracted to chubby middle-aged people, he told me. But eventually everyone becomes middle-aged and most middle-aged people become chubby. (I'm not making this up! LOL) What if my boyfriend or husband is middle-aged and chubby and I'm not attracted to him anymore? You're middle-aged. What happens? Can you still date and have sex with people your age and like it?
I told him it was a fair question but that he could stop panicking. I told him that for the most part our attractions grow with us, and while most of us never stop appreciating the beauty of youth, we learn to savor the beauty of maturity as well, and that it just happens and isn't something that requires a tremendous amount of conscious effort.
But clearly, as you point out, accepting ourselves as desirable as we age really CAN take conscious effort. More power to you for doing it!