Pardon the wall of text. This ended up being longer than expected; jump to the bottom for the concrete suggestions if you want to skip the personal context that follows.

> anyone else is feeling like this

I've been closely following environmental concerns for a couple of decades now; over 15 years ago, I felt there was a non-trivial (and ever growing) chance that the climate would, in my lifetime, end the lives of at least hundreds of millions of people. I posted about it on LiveJournal early in the millennium.

> crushing depression and anxiety

Unlike most, my struggle with negative emotions around this topic started in full force at a time when the science was far less certain than it is now. That always presented me a useful mental backstop: overriding negative emotions with the understanding that my intuitions were not strongly correlated and cross verified.

So I went forward, keeping an eye on things, but assuming that my emotional conclusions were going to be proven wrong. This is, I suppose, a concrete form of manufactured hope. (A lot of the collapse obsessed crowd use the term 'hopium'. The urban dictionary definition doesn't quite convey the meaning expressed.)

When I was in my teens and twenties, I was very environmentally focused, but it was all fairly local stuff. I worked with Greenpeace and Earth First for example.

As the possibilities of a future systemic collapse increased over time, and I started a family, I released my passion for local environmental concerns, exchanging it for a passion to maximize chances for the best possible outcomes for my family, especially my son.

That remains my strategic passion. From some people's perspectives, it is selfish, and I understand that point of view.

Based on my ongoing research and readings, the probability for civilization ending climate change in the next 30 years might be passing 50%. The story we're responding to here is one of many. If you look deeper, you will find that a growing percentage of climate scientists have passed the point of 'frantic' and are now entering the realm of depression and intellectually paralyzing anxiety.

etc etc etc. TL;DR:
....how do I maintain a positive mental state? It's not easy, but I am pretty successful at it.

Many sibling replies are concrete, practical and useful, so consider those. My passion for coming up with to protect my family's future is my take on that. I'll just add a few paragraphs of perspective, which is, for me, the most potent tool.

I know nothing to very little about the people who post on Hacker News. Even given that lack of information, I'll comfortably insist that each of us here has at least a 90% chance of living better, more comfortable, more healthy, more amazing lives over the next 20 years than 99.9% of all humans who have ever lived, including those alive today.

That is my perspective: no matter what happens in the future, I have lived and will most likely continue to live (for quite a few years) a life of enormous beauty and possibilities.

Unless (though well informed!) depression and anxiety about possible futures fucks it up for me.

Also: there's still a very good chance that the terrible futures we're concerned about won't come to pass, either for heretofore unknown natural reasons, or perhaps because we talking monkeys will get our shit together and start fixing things. (For the record: I don't have any solid ideas about what those fixes might be or how they might play out, but that is a limit on my own imagination and understanding, not on possible realities.)

In short: I'm aware of no ways that crushing anxiety and depression will improve my life.