I know how you feel. I was in a crowded Bass Pro the other day, like SEVERELY crowded and I was holding it together okay, my hubby wandered away from me, I felt okay but then someone bumped me. I was suddenly very aware of how loud it was, how many people were moving around me, I literally felt like I was drowning, I looked up to the ceiling just overwhelmed by the noise/constant movement around me. I wanted to get out of there but I was afraid to move because I wasn't thinking straight.
I stared at the ceiling trying to control my breathing until hubby found me.
There are bad days, we can't avoid them, only accept them and give ourselves a break.