Triple-check that our mortage is paid off in the event of my death, so that my wife and children will have a place to live after I (sole breadwinner) am gone.

I think the root cause is the complexity.

Split the problem into manageable chunks, then attack the chunks. Apply recursion as needed.

This is part of a more senior skillset, as some times a senior will be breaking up the problem and assigning the smaller pieces to other devs.