Lisa,
I can't do better than what others have said, so I'll just empathize. You look great and have terrific fashion sense for yourself. You're current in mind as well as body. Clothes and grooming are simply armor--or another way to communicate we're in the year 2023 (and up) without being too consumeristic, planet-degrading, etc. Or to have fun with fashion, as Angie and this forum always say.
For those reasons, I find myself remixing clothing and DMOT (hair, makeup) more than replenishing/remaking--and that, too, is current.
I do think our attitudes, words, treatment of others, etc. speak so much louder than our appearance.
That said, I feel ya' (to utter a youthful phrase). I'm in a position where I occasionally mentor young people, so they are not my peers. They look to me as an "elder," and so my age is a benefit but my currency is a pleasant/humorous plus (or so they tell me). I have purpose in my work, which is one reason I have no plans to retire. However, my work conditions are radically changing thanks to U.S. culture wars, so we'll see what comes. But for now, I'm resolved to carry on.
It is true that how we comport ourselves will not always change the minds of others. So on ageism, I guess I'll just do what I did in the face of the sexism of my youth: Deflect; pretend I don't notice; do my job to the best of my ability with a smile on my face; call out bad behavior when I've had enough, and report if/when evidence and circumstances are so egregious, they irrefutably compromise me, others, and our workplace. I'm in solidarity with you!