The question is not whether or not someone should suffer

That’s the only question. Because the standard here is “irremediable lifelong physical and/or psychological suffering”. By labeling such a person “momentarily sad” you’re not only judging them, you’re placing your judgement above that of medical professionals. You’re also lying about the necessary conditions for consideration for the program.

And aiding in a person’s suicide with their consent is not the same as simply killing them.

You can’t have an honest, rational discussion, like an adult, then there’s no point in continuing