I think what you're going through is common--I was suicidal the first week, quit caring about things for weeks, didn't see a future, etc. Make sure you're getting enough sleep, that was the most important thing that helped me the first month or two. The other things that helped were engaging in anything that requires enough concentration that it helps get your mind off it a bit. Hobbies, ping pong, playing guitar, engaging in conversation with friends, exercise. Be good to yourself. I also made sure to have background noise all the time around me. A super quiet environment is a killer.
Tell your husband it's a combination of nails on a blackboard, and somebody poking you randomly on the shoulder trying to grab your attention 24/7, every second, non-stop. Unless people experience it themselves, or have experienced some other bad chronic pain, they just "don't get it."
I think, especially initially, your brain is treating the sound like "something's wrong internally, danger!" It's like you really just have no choice emotionally when you're hit with it, and it will take time.
Hang in there!