What would it take for me to convince you that I'm repulsed by the thing-as-it-is and not its future consequence?

A source listing for the relevant code and data structures in your brain. At the moment, the closest thing I know to that is examining formative experiences, because recontextualizing those experiences is the most rapid way to produce testable change in a human being.

We can train our terminal values, and we can be moved by arguments about them.

Then we mean different things by "terminal" in this context, since I'm referring here to what comes built-in to a human, versus what is learned by a human. How did you learn that you should have that particular terminal value?

I can tell you just exactly what would happen if I weren't unhappy: I would live happily ever afterward.

As far as I can tell, that's a "far" answer to a "near" question -- it sounds like the result of processing symbols in response to an abstraction, rather than one that comes from observing the raw output of your brain in response to a concrete question.

In effect, my question is, what reinforcer shapes/shaped you to believe that it would be bad to live happily ever after?

(Btw, I don't claim that happily-ever-after possible -- I just claim that it's possible and practical to reduce one's unhappiness by pruning one's negative values to those actually required to deal with urgent threats, rather than allowing them to be triggered by chronic conditions. I don't even expect that I won't grieve people important to me... but I also expect to get over it, as quickly as is practical for me to do so.)