I consider myself to be a rational person which directly contradicts the fact that I have anxiety. I feel like a lot of people dont understand how an otherwise rational person could possibly have such a disorder. It's really hard to explain in words what it feels like to constantly be at war in your head.

Having anxiety and knowing that the anxiety is irrational is like having a faulty fire alarm in your head. Maybe it's going off all the time or maybe it only sets off every now and then. You may know that the fire alarm is broken and that nothing is wrong, but that doesnt stop the fire alarm from screeching anyway. You can't rationalize with a faulty fire alarm. 

So maybe the fire alarm is going off right now and you know it's faulty, so you start trying to calm yourself. "The house isnt on fire. Everything is okay. You know the alarm is broken. Just take a deep breathe and calm down" and maybe that works for a bit. But it keeps screeching. And it keeps going and going and going and going and any rational person would think after such a long time that maybe something really is wrong. Nobody can stay sane with a fire alarm blaring in their ear 24/7, right?

So you evacuate. You call 911. You let the panic of losing your home in a fire wash over you. But then, your house isnt on fire and everyone thinks you're a drama queen because you know that the fire alarm is faulty, so why dont you just shut it off instead of worrying about it?

Because you cant shut it off.