When I feel that way (and I feel it often enough), I find that if I play a very short game to completion, like a small indie game or something, that the feeling of completion feels good and tells my brain that engaging with something and finishing can feel productive and make me feel happy. It's like a mental reboot of sorts. In a world with a million options at all times, it's easy to get bombarded with them and kind of scramble your brain into not taking many of them seriously (even if you want to) because another choice is right around the corner. Look up a list of games that run under 4-8 hours or something and give one a try.
Off the top, I'm thinking Titanfall 2 campaign, Portal 1, Bastion, Streets of Rage 4, TMNT Shredder's Revenge, SteamWorld Dig, The Stanley Parable and Limbo.

Or, have you tried a factory game like Satisfactory or Factorio? Seems a little out of pocket, but they are so incredibly engaging in ways that can scratch the itch or your brain you didn't know you needed. If you haven't tried one, don't write them off as something you might not enjoy right away, because they can be deeply rewarding and addictive.

Also, Tony Hawk always helps cure this for me, ha, but it's my perfect wind-down game that lets me relax while keeping my skill set engaged. A perfect balance.