I don't particularly want to put it behind us because it is in fact relevant to the discussion.
More relevant, however, is that you have inherently misread the point of the hobby. Or, more accurately, your DM's interpretation of the point of the hobby, there is no objective point.
Some DMs like number crunching games. Games where you are given free reign over your character and are expected to work out the percentiles on every action you take to win, because no punches are being pulled, and you will lose otherwise. But the question is, do you actually define the ability to perform basic math and look through rulebooks for hours as 'personal profiency'? It takes about as much 'skill' as blackjack does. It has a win condition and failure state, so it fits your definition of a game, but it's, well, boring, in my opinion.
Some DMs like storytelling games. Games where the intention is to create a narrative, and the system is just an engine for this. Oh, there might be a chance of losing, but generally even being defeated or failing won't actually halt the story, it will simply take it in a new direction. The win condition and failure states here are not well-defined. You're expected to create your own win conditions and failure states from your immersion in the narrative.
Personally, I prefer the latter since it creates a more fulfilling experience for me, rather than winning at a game because I memorised all the options and made all the right moves, but I acknowledge that there is no objective truth to this, or, well, anything.
But what it boils down to is the choice I proposed before. Accept that this issue you have taken is detracting from your happiness. After that, you can either opt to find meaning from this hobby as you have before, or opt to leave the hobby and find meaning elsewhere, since you have explicitly said that you need meaning for enjoyment to be possible.
Final option, of course, is that you just have a bad DM.