TL;DR focus on the things you can control and do literally anything to try to improve things
The thing that causes trauma isn't the bad event but the helplessness that accompanies it.
The main (and sometimes only) tactic that we are taught for dealing with problems is to find an intermediary who can do things on our behalf; seek the nearest authority who will take up your cause. Viewed that way, the fact that institutions and authorities are failing is disempowering; the problem is impossible because the schools/cops/companies/non-profits/politicians/media/etc aren't helping. The only option that perspective leaves you is to take the blows and hope you're strong enough to last until a better intermediary arrives. That shit will wear you down real fast.
We need to unlearn the dependence on intermediaries. We can't stop the bad events from happening (and boy are they happening) but we can combat the helplessness. The antidote to helplessness is exercising agency and feeling control over our actions and their consequences. Find a way you can make things a little bit better and then show up and do it. Anything is fine, if there's a cause you're passionate about then do that, but if there's not then pick something you're kinda sort of good at. Write, draw, make phone calls, create memes, cook, drive, listen, etc. Any skill, no matter how small, can be leveraged to improve the world around you if you're clever about it.
The fight is the point.
Taking action to control what you can is powerful. Maybe you'll succeed and maybe you won't but taking action is where you'll find resilience. If what you do doesn't work then learn from the experience and deepen your understanding. You're not failing to solve the problem you are building up your capacity to tackle it and that shit takes time. Pursue this as vigorously and as passionately as you are able but also know that it's okay to take breaks and step away sometimes.
Also, humans are social creatures so if what you do involves other people that's even better.