>> ...but I've taken the time to prepare a set of scenarios under which I would no longer want to live, and think about what would need to be taken care of...

I believe professionals would categorize what you wrote there as "planning suicide". So long as you have not started "taking care of" those things you have not begun executing your plan. Planning is a rather big step beyond contemplating - I hope you're doing better now. You may also want to consider that actually getting your affairs in order could be an enabler.

See, this is exactly what I am talking about.

It's evaluating a set of contingencies. Like, the general staffs of armies make war plans that they will never execute, unless the particular parameters fall in place, all the time. To do otherwise would be irresponsible.

I think what is missing is what set of circumstances would trigger you to execute your plans. If it’s “world wide epidemic which causes extreme pain and suffering with less than 5% chance of survival” that is one thing. However if you are planning your suicide in case you lose your job or your significant other cheats on you then that would be concerning and reason to seek help.

There's no need to imagine such an epidemic. We're all going to die. And sometimes that involves extended periods of pain and suffering, with no chance of survival. In civilized places, voluntary euthanasia is available. Elsewhere, one needs to plan ahead.

We need to decouple the concepts of "assisted suicide in cases of terminal illness" (may not be assisted, may not be terminal) from other types of suicide.

The public health responses to you should be very different to the people who experience rapid onset despair.