Very late to this, but:
You sound like a machine built for a different set of circumstances. Wartime, or famine, or slavery; or most likely, a heavily religious society.
I would guess you’re mostly nonreligious. But you have a lot of mechanisms left over in your personal acculturation from when religion was important for your ancestors. You took out the formal religion, because that’s not needed so much these days, but still have a lot of underlying mechanisms, like a conviction that there is such a thing as an ultimate answer, which made sense when the accepted ultimate answer was God.
I would guess that you enjoy learning and regularly investigate new things, but one of the mechanisms that generates your motivation is actually an old outdated attempt to find God, which you are no longer trying to do. Rationally, you search for the limits of the set of ideas you’re currently investigating, find them, and move on, in accordance with modern liberal arts thinking. But there’s a twinge of disappointment because you were being driven partly by leftover religious mechanisms that were hoping for Ultimate Truth. The repeated disappointment of the old mechanism leads to tiredness, and a feeling that real meaning keeps not being there no matter how much you keep reading interesting things on the Internet. There may also be a buildup of resentment that your trust has been repeatedly betrayed.
Just a thought this morning. I recognize a lot of what you’re saying. My parents were missionaries and it has proven impossible to escape all of those influences.