As another commenter alluded to, inflicting trauma and depression on perceived enemies is an intentional tactic of oppressors. Therefore any moments of joy are acts of resistance against oppression. Depression is a valid response, but it isn't always helpful to yourself or others. So trying to find ways to cope can improve your situation.

Two things I find helpful for coping are being in community with people who share my values and volunteering to try to improve my corner of the world. I find both of these things through my Unitarian Universalist church. There's no expectation to believe any specific scripture, just a shared set of values. The first principle being all humans have inherent worth and dignity. Our congregation has people who identify as atheist, Christian, Jewish, Muslim, Buddhist, several types of pagan, etc. Our music program is also a big bonus. Find a congregation near you, they can vary based on the local membership and many stream services so you can check out the vibe before going in person.

It's an understandable reaction, but it's not ideal or effective. In fact, depression and apathy is one of the key mechanisms of keeping a group oppressed.

Fighting to maintain power is costly and risky, but if someone can make people give up hope and stop struggling, then they can do what they want to them.

Opposite is also true if you're Chaotic Evil