OP your life sounds a lot like mine...now. And it sounds calming and pleasant and that you really know yourself. No one else does, don't let them think they know better.
I've had the marriage, the children, the divorce, the long term loving [yeah, right] relationships, the close friendships [until someone else comes along], family members support.
I now choose to be on my own [I'm much older than you]. I do not like socialising, pubs, noise, traffic, kids, badly behaved dogs...
I've had it with trying to please/adapt to 'friends', partners needs and wants, when who I am is being ignored/used. I can't do it any more so it's no real loss.. Losing family members does hurt...mother, aunt, cousins, half brother and sister, who are either dead or in their own worlds, forgetting I'm here. Fair enough.
I wish I'd found myself sooner but glad I experienced what I did to educate myself and know the difference and the relief of not doing it any more.
I've felt too selfish before to have this peace and do what I want to...walking in green spaces/beaches, reading, internet rabbit holes, good TV, my lovely home, caring for my garden. Yes, seeing adult sons and grandkids now and then but very infrequently now due to their busy engagement with the world. They're loving it, I'm happy for them.
Always something vaguely missing. I think it's a pet but not certain if I can commit long term to anything anymore. I was an only child too [until 12yrs old] and realise that that state of being...finding things to do and feeling quiet and comfortable in my own company, no one interfering, constantly there or giving 'feedback' [criticism for my choices and who I am], is more normal for me.
OP you have missed a great deal of angst, stress, neediness of others, duty, and resentment by living your own life. it all sounds good to me. If something needs changing it will come along in some way or other, even from a sudden thought, something you read or hear etc. etc. Life can change in a minute, meanwhile enjoy.