Personally, I’ve yet to see a single American successfully use guns to protect any other constitutional right from government infringement.

The Battle of Athens is probably the most uniquely clear-cut example of what you're asking for, unless we count the American Revolutionary War itself.

Other successful examples mostly involve activists using non-violent protest to push for change, while using firearms to protect themselves from violent reactionaries that would otherwise murder them. Notably, the civil rights movement of the 1950s and 60s. For a modern example, there's various "John Brown Gun Clubs" and other community defense organizations providing security at LGBTQ events against fascist groups that seek to terrorize event-goers.

It's also worth noting that resistance is often worthwhile even if it doesn't result in unqualified victory. For example, the Black Panthers' armed cop-watching activities saved a lot of Black folks from brutal beatings at the hands of the police, even if the organization was eventually crushed by the federal government.

I have seen lots of examples like Waco and Ruby Ridge, where the government should have tried harder to deescalate, but in the end, everyone died. The closest example I can think of where the government did backoff was the Bundy standoff and all those guys were “defending” was their ability to let their cattle graze illegally on federal land because they didn’t want to pay for access like everyone else.

It sounds like you might be in a bit of a filter-bubble. I don't mean any offense by this, it's a normal thing that tends to happen to people. If the news sources you read and the people you talk to don't mention these things because it doesn't mesh with their worldview, how would you hear about them?

just made it easier for police to pull the trigger because they're all terrified for their lives.

Police brutality isn't a product of fear. They treat armed crowds with more respect than groups they assume to be unarmed.