Your site is the very definition of a content farm, and worse yet, it's a niche content farm. No one visits content farms intentionally, they stumble across them via searches. Google is trying to kill the incentive to create these kinds of sites.

Some of your content might be written by real authorities, but it's still lightweight and relatively thin. Compare it to Wikipedia if you want to see the standard you have to meet.

Even if you do manage to game Google again it's likely you'll get slapped down in a future tweak. It's an arms race and they're not playing around anymore.

Build something that's strong enough to stand on its own.