Beta blockers aren't great for sudden panic attacks. I took them for years, and while they're great for toning down the anxiety baseline, they don't even remotely approach benzos when it comes to mitigating severe panic. Sadly the only medications you can reasonably get out there that will address an incipient or in progress panic attack are benzos.
There are other supplements/medications that are helpful (phenibut is my goto since I no longer wanted to take benzos), but none of them are fast acting or powerful enough to stop something that's already happening.
There are other supplements/medications that are helpful (phenibut is my goto since I no longer wanted to take benzos), but none of them are fast acting or powerful enough to stop something that's already happening.