1.) Start dating. It might be a drag and maybe embarrassing at times, but obviously not being a loser having saved up half a mil in 10 years, you will probably find someone. Don't buy into that Hollywood "soulmate" crap. More likely than not there is already someone you know or at max someone one graph edge away which will be a perfectly fine partner for the rest of your life. So finding that person will keep you occupied for 2-5 years.
2.) Get kids. Having never imagined to be a father and now having three kids, I have to admit I always feel sorry for people who don't have kids. I have a hard time to see any relevance in a life without children anymore. This might be complete bs but certainly floats my boat. I got my "finding meaning in life" completely covered by getting those three buggers into a good position for their life. That will keep me busy for the next 15 years.
3.) Don't take your job too seriously. There is Jeff Bezos and Bill Gates and Henry Ford but for 99.99% percent of the people here on HN (me and presumably you included) what you do in your work life will not really matter for generations to come. It pays the bills, it should be interesting enough not to bore you to death, you should have colleagues that are in their majority "friend material". That's it.
I always imagine my live as a pizza with three slices: personal (some sport, watching movies with friends, reading books, etc.), family and work. Ideally, each one should be about a third of the pizza, ie. have a third of your attention and time. There are times when this is not possible but it should be the state you are striving towards.