I definitely relate to what you're feeling here. Looking back (waaaay back from 68), nearly all of my regrets are for the opportunities I missed, the possible mistakes I didn't make. But mostly I believe my choices were consistent with who I was and what I was ready for.
Here's the good news, though.
One, sex gets better as you get older. You learn your own body and get over the self-consciousness of thinking lust is about youthful perfection. You develop skills, both physical and emotional, as well as knowledge, patience, and awareness of how deeply hilarious the whole sexual enterprise is. You learn to give and to receive and to appreciate the way you honor your lover with your hunger.
And two, married sex can be fantastic and stay that way for years. It will probably ebb and flow rather than stay hot year in year out, but in my 25-year marriage to my second wife, the quality of our time in bed together definitely did not diminish. I described it as a series of monogamous affairs with one best friend.
So congratulations, Gigi, and l'chaim!