over stimulated

I've been dealing with  a lot of people recently; every time someone speaks near my ear, my body feels a surge of rage and it makes me feel a sharp pain in my head , and being around people drains all of my energy. I'm 39 years old and believe my qualities have gotten much worse since my mother died. I'm using the entire snap a wrist band on my wrist thing when I'm over stimulated out in public , which occasionally works but the affect  wears off. My therapist suggested carrying ice cubes in my hands as it causes a pain and can distract you, but I don't have access to ice when I'm out, which is why I laughed could possibly work if I was at home. Does anyone have any decent strategies for distracting themselves when they are overstimulated at work or in public? I have noice cancelling ear plugs but I can't always wear them due to the nature of my work 

Thanks in advance  Gem