Stoicism teaches that you should strive for virtue, but cannot expect any particular outcome. You can't have your happiness and contentment depend on factors outside your control, or you will inevitably be unhappy. Try to be virtuous, try to do the right thing for the right reasons, and if the outcomes are not what you hoped for, then at least you tried. Stoic virtues are wisdom, courage, justice, and temperance.

That's just called being normal

Like, I'm aware that the world is fucked. I can't really change that, though I can do my part.

And the world is not irreparably fucked. Just probably irreparably fucked during my lifetime.

We'll get it together eventually.

But the point is, why stress, it doesn't help anything. Don't worry about it. Either take action or don't.

Well, I can't speak to a middle ground, but I can say that my anxiety is at its worst when I stall. If I examine what gives me anxiety and take steps to prepare for it, that alleviates the panic.

I don't know what eats away at you so I can't give you the perfect guide. Only you can say what causes you anxiety, and only you can prepare yourself for it.