Explaining it…?

How do I explain to my stepdad that if I start having a panic attack, he can’t just keep talking or asking me questions like nothings happening? It’s happened quite a few times, and I begin to panic, but he acts like he doesn’t even know I’m having them. I love him with everything in me, and he’s there for me for everything (except seemingly this) and I don’t know how to say it in a polite way, or even… at all. But my mom has had to step in multiple times to tell him to give me a few minutes and I’m worried that with going into my first year of high school, the panic attacks are only gonna get worse, and I just wish I could find a way to explain that having a panic attack isn’t nothing, and can’t be treated like nothing. For anyone who reads this, I don’t want anyone to be like “oh he’s so mean” or “tell him to chill out” cause I hear that all the time. I just want some advice so that we can both grow as people. Having anxiety is hard enough as it is, I just want him to understand better.