For a while I've been keeping my eye out for short-circuit approaches that aid in questioning the assumption that "this existence is it", and provide a useful level of signal in circumstances where I'm significantly preoccupied with arbitrary suboptimality and don't really have the opportunity to focus for whatever reason.

For what it's worth, I haven't found anything yet. It seems that the be-convinced-in-ones-own-mind problem requires focused consideration by definition.

Just saying.

For my own part, I have this visceral unease that I don't think will go away until I have absolute (end-to-end, closed-loop) confidence in Something.

Today I read Yasmeena's Choice, by Jean Sasson (https://www.goodreads.com/book/show/18376565-yasmeena-s-choi...)

There was a girl, Lana, 16 years old. She fought, all the way...

It's horrific, and sobering, and may help you to get a perspective on your troubles.

That's a rich assumption, perpetuated by those who choose comfy ignorance. The ultimate gift is reason that lets us foresee consequencies without experiencing them. Also, someone who has nothing to lose wouldn't live like that. If I had a terminal stage cancer and one month left, I wouldn't sit and waste time.