Hi everyone, long time lurker but first time poster. 
I was hoping to get some advice on controlling or reducing an anxiety attack once it occurs. 
I have trouble with crowds and shopping centres in particular make me very anxious. It’s gotten to the point where I can’t go to any enclosed public space. When I have an attack I panic rather quickly, and usually cry / hyper ventilate. 
It’s made it difficult as my boyfriend sees it as too much work to deal with the attack in order to get our shopping done.
I can feel it slowly destroying my relationship with him, as he feels that I am over reacting and that my anxiety is keeping in isolation.

Do you guys have any advice on how I can calm an attack when I feel it coming on?
At the moment the only thing that works is removing myself from a situation by running to the bathroom to cry but this is a less than ideal solution. 
Any advice would be greatly appreciated 
Thank you