When I think of the Big Questions like The Meaning of Life and Purpose....

[AverageJoe90]

7. I do sympathize with you, but I also would like to add something.

I think that while feeling some pessimism every once in a while really isn't all that bad for you, it isn't wise to let it dominate your life, either.
If I may, I would like to use the examples of the Civil Rights Movement, and those who fought for labor rights; they all knew that they had a long and tough road ahead of them and that there would be plenty of obstacles that the malcontents, crooks, and other ne'er-do-wells in the Establishment would throw plenty of obstacles their way and that it would be an enormous challenge to wake the majority of Americans up from their apathetic slumber. And yet, somehow, despite overwhelming odds, they succeeded.
The same goes for nuclear disarmament as well; Nuclear war, TBH, was something that we HAD to avoid at all costs; even a limited exchange would have done perhaps as much, even more damage in perhaps just 2 hours than 6 or 7 degrees of climate change would over 2 centuries....a full-scale nuclear war would make that look like an absolute cakewalk. And once we truly knew & understood the dangers, we really began to ramp up the action.
Right now, in terms of climate awareness and action, I would say that we are roughly about where we were in the late '60s, early '70s: we're starting to fully understand the dangers(no thanks to the scaremongers, though), but we haven't yet taken truly majorly significant action just yet, though it certainly is on the horizon.

And I've noticed, too, that some of the worst forms of nihilism seem to come right from the mouths of those who've completely given up on life.....and yes, this would include most climate doomers in particular(especially the wackos pushing New Agey theories such as "Near Term (Human) Extinction" and quantum climate shifting, etc.), as well as a few(a FEW, I should stress!) factions of the Progressive movement who've gone into full-on "freak out" mode.

Again, don't give up, no matter how bad things might seem; the people who have made the most progress in getting things done, are those who had real hope for the future.....just look at MLK, or the Wobblies.....