I absolutely hear you. I think that if I were single again, I would be using a modified strategy from back when, so essentially hoping for the best but planning for the worst.
In concrete terms, that would mean working out what I needed in my life in order to be happy if there were no men on the planet. I would construct a life for myself where I was fulfilled, had company when I wanted it, for example by finding sociable activities, and where I was happy enough in myself to continue that way indefinitely. Where a man would be a nice extra, but not the main focus. It might take some therapy or counselling to work some of that out, but I would get there. And the chances are that in the process of doing all that, I’d meet someone who had similar interests and aspirations. So maybe do more of what you enjoy and you’ll find someone who wants to enjoy those things with you.
Companionship and connection also don’t have to come from a man. I look at my mum, who is a widow, and she is not lacking for either. My parents split when they were in their late thirties, and Mum ultimately decided to use that time to do something she really wanted to do for herself while she had no bloke and her kids had left home. She went off volunteering in Africa, and it’s only by chance that she eventually met my stepdad in that period. She wasn’t actively looking, and in fact by that point it wasn’t even convenient, but she was so much herself that she was absolutely bloody magnetic to be around. She had strong female friendships that sustained her, and my stepdad essentially proved to her that he would be a positive presence in her life.
She’s now in her late seventies and has friends and activities where she connects with other people regularly, as well as having my brother and I. There is a widower a few doors down from her who has rather clumsily indicated that he would like a relationship, but she’s gently pushed back on that because she’s happy with the life she has, even living on her own. She chooses when to seek company and when not.
I guess I’m lucky that she is such a positive role model of how, even when your husband has essentially run off with his secretary and been a shit, and given a massive blow to your self-confidence, you can go on to live a happier life of your own choosing, unfettered by a man who has to be the main character instead of an actual partner. In those years after the split, she always said she was done with men and would never remarry, so she was going to build the life she wanted. It has served her well and also led her to the love of her life, my late stepdad.
So whether you think in terms of just sex/FWB, or deciding to create a life that makes you happy and fulfilled, there is likely someone out there that will go out of their way to prove to you that they deserve to be in your life. You’ve just not yet met them.