If instead I go deep on what I enjoy, I am happier in the short term AND long term. When I was younger, I would "waste" time on strategy/tactical games. But I think I actually gained some long-term planning skills from this, and developed a taste for "slow thinking" from this activity. And now those games are boring to me.
Last weekend I buried my head in functional/algebraic programming, even though my conscious brain was saying it was a total waste of time and distraction from my real tasks/goals. From the experience, I've learned that functional programming really isn't the silver bullet I want to believe it should be. But I trust myself enough to believe that even if the payoff isn't obvious, or even if it doesn't apply in my professional life, that my brain giving me enjoyment for the activity is enough of a signal that it was time well spent...even if I really can't justify it to anyone including myself.
You can point yourself in a general direction by setting up your environment towards that direction. Buy books in things you're interested in even if you never end up reading them. Give your body sunshine. Never go grocery shopping when hungry, and fill your fridge only with good foods. The key to letting your unconscious brain take over is that you only give it access to the sugar that your executive planning brain believes will work.
I'm also "ADHD." Quotes because after 30 some years living with the diagnosis (and reconfirmed, both by others and myself), I still don't really know what it means. Something sometimes discussed is "hyper focus" for ADHD folks. Honestly I think this is just a normal expression of that other quality: a total inability to engage with something once it becomes boring. And excitement for those things that retain interest. Naturally, things that are confusing or complex tend to be impossible to initially approach, but gain momentum as you gather more clues and understanding.
I have great sympathy for those that try to go "the hard way." I did that before I got into software development. I denied my misery (of not software dev) for a decade because I understood that hard things are hard, and believed my misery would pay off.
Turns out, I didn't have all sides to the equation. Hard things are hard AND hard things that you are passionate about can be your way to contribute to the world. Doing something that is "hard" BECAUSE it is hard only because you have no passion in it is a bizarre but plausible scenario for what I imagine are many HN readers.