I do the things I do because I like them and others find at least some of them valuable, and there's probably a significant chunk of biological determination behind my enjoyment of those things. And that biological determination is enough intrinsic value in my "meaning games" to satisfy my existential angst. I went on this whole meaning search in my early 20s which I'm just completing and came to similar conclusions, but apparently on a lighter note after going through my Debbie Downer bouts.
(1) Sunlight and exercise. (2) Friends and good conversation. (3) Women. (4) Pursuit of goals. (5) Altruism.
Rinse and repeat. Good enough for me. When I'm feeling down, it can be at least partially attributed to not checking one of the above boxes.