[TeMPOraL]

Doesn't work for me, Firefox restores tabs from before restart. I could turn it off, but it invariably comes helpful for when Firefox (or the PC) crashes.

My current solution is that, through a stroke of luck and a lot of pent up frustration, I've managed to habituate the following behavior:

WHEN I notice I've been procrastinating for too long, OR I'm getting anxious about so many "open loops" in the browser, OR I lose track of specific tabs I know are open and spend more than two seconds looking for it, THEN I find the last Actually Important tab (usually somewhere between the third and the tenth from the left), right-click on it, select "close tabs to the right", and confirm the closure of 100-200 tabs.

I do this a few times on a typical week; because its habituated, I do it fast enough that the FOMO of "but I actually wanted to read that, and that, and that" doesn't have time to kick in.