I channel the despair, anger and misery into working on solutions to help marginalized peoples. I don't have all the answers to the world's problems, and I can't solve it all, but I can show the people who might have the answers that there is someone in their corner who supports them in their efforts. Even if those people haven't been born yet, demonstrating the power of empathy and collaboration sets them up to choose constructive paths. If I give up on them, then it becomes much easier and more likely that they will choose the same anti-social self-interested motives that are destroying us all. But, if they are going to be able to make that choice at all, they need to be in a position where they aren't in survival mode all the time.
We're all just organisms who exist for a brief flash of time on a galactic scale, ultimately this is all meaningless. But as someone who identifies as a bit of an existentialist, I make my meaning. You can too.
It also enables me to leave the weed for wind-down time, mostly. Depends on how badly my health is doing, and it's pretty variable.