Is it normal my boyfriends extreme social/crowd anxiety in malls

He will freeze and refuse to move, until he snaps out of it and wants to get out of the situation immediately, usually being a little forceful and making me leave with him. If someone bumps into him or startled him when he's starting to enter panic mode he lashes out, he's broken two noses and a jaw since I started dating him. He goes into some sort of fight or flight mode and it can be really scary sometimes, so I rarely push him to go shopping with me.

He grew up in Sparta, Greece before moving to the states and says that crowds were always a bad sign there and it's kinda stuck with him. He's absolutely fine any other times, but just turns into a whole other person in crowds. He's 6'10" and a buff guy so he gets a lot of stares just because ya know you don't see people that big all the time, but he takes it as people are planning to attack him or rob him and he freezes up or panics.

I want to help him when he gets this way, but if I try to hold his hand or lead him away he squeezes and won't let go until I'm basically crying and hitting his chest to knock him out of it. It is scary, but I know he doesn't mean to. I really just want to help.