I experienced this feeling too OP. The sudden realisation of aging and it completely threw me. I think it was because for the first part of my adult life I was always focusing on the next milestone. University, travelling, getting a real grownup career on track, meeting someone, buying a house, getting engaged, planning a wedding, getting pregnant, parenthood, moving to a bigger house, having another baby......
Then suddenly that was that. Now what? I was 40 and knackered and old and fat and unfit and how the fuck had that happened. I also had a lovely husband, happy marriage but the realisation hit that I would never shag a young hot bloke again.
And I had enjoyed very much the shagging of young hot blokes in my youth.
It was like a midlife crisis of sorts and I actually had a week where I couldn't eat and kept crying. DH was very sympathetic. "I don't want to shag someone else but I want to know that I could if I did waaaaaaahhhhhh". And feeling pathetic and ashamed and guilty for feeling that way.
It passed. Covid hitting helped put things into perspective. But I hear you. It's a gut feeling and it's not pretty but it will pass.
I had a period of questioning and talking with friends about what societal expectations were feeding into this shitness and I shed a lot of them. I genuinely don't give a fuck now about how I look other than to please myself with things I think are lovely to look at, jewellery, makeup, hair, clothes are for me. Thank you Caitlin Miran for that perspective. I do Pilates because I like it, not to be thin. Bloody revelation. And I feel like meeting new, amazing women, mainly awesome work colleagues and school mum's actually, and building friendships with them has replaced the excitement I used to get from meeting hot blokes.
I rediscovered solo cinema visits and theatre. Me and DH are planning our bucket list for travelling with the kids and also fantasising about retirement. The next milestone. In 22 years ☺️