If you don’t mind the feeling of having ear plugs or earbuds in your ears, I have found that the Flare Audio “Quiet” earplugs really take the edge off the world. They don’t prevent you from hearing in general, but rather they dramatically reduce frequencies above some pitch (I forget), which my brain often interprets as pain or like I’m being attacked.
Not spending my day under constant “assault” by the sound of fans or my young child’s high-pitch excited voice REALLY helps me to not get overwhelmed so easily.
I had several days in a row recently where I’ve gotten really panicked and close to snapping because of feeling overwhelmed, and I started wearing these again and it made it much, much easier to come down from that feeling.