Your concern about doomsday projects is very welcome in this age of high existential risks. Suffering in particular plays a central role in that game. Religious fanatics, for instance, are waiting for the cessation of suffering through some kind of apocalypse. Many negative utilitarians or antinatalists, on another side, would like us to organize the end of the world in the coming years, a prospect that can only lead to absurd results. For the short term, doomsday end suffering projects can plan to eliminate life (or at least human life, because bacteria and other small creatures would be extremely hard to eliminate on this planet), but I doubt that they would want to have consideration for "the conditions for the evolution of life throughout the universe", be it only because they are completely unable to do anything about that, or because they are anyway not rational at all in their endeavor. So, there is a race between us and the doomsday mongers: I think that bringing a solution to suffering is our only chance to win in time.
The solution to the problem of suffering cannot be to eliminate all life because lifeless evolution created life once and it could recreate it, and million years of pain would come along again before another intelligent species like ours re-appear with technical power and has a chance to resolve the problem of suffering by controlling that phenomenon through conscious rational efforts until the end of this universe.
"I’m not sure what I should do with this information. There is no cosmic justice in suffering on behalf of others, in living burdened by its unthinkable urgency. Yet there is something like cosmic justice in acting to reduce the worst suffering in our world. I do not even know where to start."
We are numerous, since millennia, who want to do something about suffering. Why not work together in an enterprise for an optimal alleviation of suffering in the world? That is what the Algosphere Alliance is proposing: to organize the alleviation of suffering, steadily and sustainably.
More directly addressing the point of your text, Aaron, I suggest that we use our thinking power to abstractly think the urgency of suffering so that as a consequence we can act theoretically within the framework of a science of suffering (algonomy) and practically within the framework of a concrete all-encompassing organization (algonomic alliance).
I am all in favor of chronic pain being a cause area. In itself, that would be a good thing, but there is another, more important reason: this might help us to realize how exactly physical pain and most concerns in EA are related to the arch-cause of suffering. The very notion of EFFECTIVENESS is at stake in this matter. In my opinion, the whole field of pain research and management has not decisively advanced since the 1970s, when I first became interested in it. I believe progress is hindered by a fundamental problem in pain theory, as explained in https://www.academia.edu/7443845/The_Study_and_Management_of_Pain_Require_a_New_Discipline_about_Suffering. For those who'd like a TL;DR summary: simply starting a science of suffering should urgently be made a cause area.
Yes I know, thank you ADS, but I rather have in mind something like "Toward an Institute for the Science of Suffering" https://docs.google.com/document/d/1cyDnDBxQKarKjeug2YJTv7XNTlVY-v9sQL45-Q2BFac/edit#