In a way quite similar to a sense of victimhood, I think that sometimes people enjoy feeling overwhelmed. When you face overwhelming circumstances, to a certain extent, you are relieved of any responsibility to act effectively. If you accomplish anything whatsoever, it will be deemed nothing short of miraculous. In overwhelming situations, there is a kind of inflation of the currency of action, and a deflation of blame and accountability. After all, it is an impossible scenario; you can feel brave and noble for doing anything at all, and no one can blame you for failing to accomplish anything of any substance, given the odds.
If you think about it; when you focus most of your efforts well beyond your actual sphere of influence, it is a very low-risk proposition. That is the beauty of being overwhelmed; everything is beyond your sphere of influence.
It is a somewhat dissatisfying reality that one must focus on what one can actually do, if one is to be effective. The impact may be small, it will definitely be limited, but it will be real. Necessarily, when you focus on something, you obscure your attention to what is peripheral to it. But that is how you get things done.
All the peripheral matters may well be important, they may even be urgent; but they are peripheral to your focus because they lie beyond your actual capability, and if you were to attend to them, you would attend to them badly. So you must decide what to focus on, based on its being both useful and possible, and yes, you have to stick to it. You have to maintain your focus until you succeed.
There is nothing saintly and admirable about taking on problems you cannot solve. It is arrogant and self-deluded, and it is ultimately harmful. Not only will you not solve those problems (or perhaps even make them worse) you will neglect attending to problems you might actually be able to solve. If you are going to be an activist, humility is at least as important as idealism and compassion. Be humble enough to know your limits, work within those limits, and do not over-extend yourself with grandiose notions of “saving the world”.