It's really hard OP and I'd say it took me a good 5-6 years to accept that it wasn't going to happen and to be happy with what I had.
In my case it was different because my lack of DC was down to infertility. So I knew that there was no hope of a biological child, and that cut off one avenue of useless hoping.
I did still have the hope of meeting a man with DC of his own and building a step family. I did meet one, but he turned out to be a cheating bastard 😒 and after 4 wasted years I had to give up the fond relationships I had developed with his DC and DGC.
During this time I had continued contact with my late husband's DS and very luckily for me he has chosen to accept me as an adoptive mum (very long story). It has been a very difficult journey especially without a partner and with the knowledge that he will probably not ever be able to live independently and give me the GC I still crave to create a big loving family.
These are the things I have chosen to focus on:
My career - you already mentioned you had a good career. So did I. I'd say concentrate on your next steps up the ladder (or sideways) and take action to make it happen. Step up and ask for projects. Offer to cover more senior colleagues during sick/holiday leave. (I did this a couple of times during my last corporate position and after said colleague came back to work, I found I was still being thought of as the same grade as him. "Oh are there some interviews to be done? Furiosa could help out I'm sure!" "Furiosa, would you be able to have this Difficult Conversation with one of your colleague's direct reports? Thanks!"
I realised that animals gave me an enormous amount of love and satisfaction. I only had a tiny flat so it was just (at the time) me and my grumpy bitch cat. So I started volunteering for Cats Protection once a month on a Saturday. It was great for meeting new friends (human and cat!)
I now have a bigger place and I breed fancy rats :) Caring for them gives me a huge amount of satisfaction and love, also a lot of anxiety and vet bills! But it's all worth it.
I've never been that interested in travel, but I definitely "date myself". I go to the cinema on my own, I go out to eat on my own (and if I've hit my financial targets I treat myself to a "fine dining" meal once a month.) I go out for walks on my own, I go to the gym on my own. I also spend a fair amount of time speaking with (much less frequently meeting) the few friends I choose to cultivate.
I appreciate right now to you this probably sounds like "Blah blah blah be thankful for what you've got and work on yourself." But I just wanted to let you know that it may take some years to accept the position you're in, but it doesn't mean you'll be unhappy forever or always be wishing things were different.
I wish sometimes my life were different and this particularly kicks in around Xmas - I idolised the Xmas my Grandma always provided and I always wanted to provide the same to my loved ones. Wasn't to be. But that doesn't mean I spend all day Xmas being all depressed about it. I enjoy spending the holidays with my D(S)S and planning what dishes we're going to have, cooking them together and he's in charge of our viewing schedule - I'm in charge of our gameplay schedule. (Monopoly is the current fave!)
It will take some years OP, but you WILL get to a place of acceptance. In the mean time, please take these 