I don’t think the cognitive techniques work once you reach panic, you need to rely on behavior like breathing techniques until you calm a little then you can go cognitive.

It’s best thought to use th cog techniques before you panic. So say you notice a different heartbeat and think it’s bad, well what is th evidence it’s bad, what if it’s perfectly normal? Could there be alternative explainations like you were exercising or you’re experiencing anxiety or whatever. Is there any benefit to the thought? What are the costs?

If your friend were having this issue what would you say? And in your case what is the most realistic possibility that could happen.