That's the CBT theory. It's that simple: the thoughts in your head are controlling your emotions. Think about what you are thinking when you are feeling anxious and try to counter those negative thoughts with logical ones.

Why are you able to go to work and the bank? Because you have to. So you forced yourself to stop those thoughts enough to let you do what you absolutely have to do.

I'm no better at controlling the thoughts that trigger me to have total anxiety attacks. I get it and feel for you.