@bearfan
There are many great suggestions here.
I'm sorry you are suffering so badly. I was in the same exact position no more than two and a half years ago.
It was necessary for me to wear sunglasses and earplugs underneath soundproof earmuffs while keeping the blinds closed.
I couldn't watch television, much less listen to music. Even the briefest conversations with my wife were painful. And the list goes on.
A change in diet may have been slightly impactful overall, but my saving grace was meditation. It helped quiet my mind.
The process was gradual, more gradual than I would have liked, but now I'm to the point where I can function mentally, and for the most part, with a clear mind. And my overall anxiety is greatly diminished. I can even self treat myself.
The only way, and the simplest way for me to quiet my mind is to focus on two separate things at one time, that way, all of my thinking thoughts are eliminated, if only for a short time.
Example:
Focus on an object with your eyes, while also concentrating on relaxing your shoulders.
Do this for 30 seconds, keeping your eyes focused and your shoulders relaxed.
The more you practice, the longer you can do it, and without all of these random thoughts ruminating in your head, you can more easily relax.
The feeling of being overwhelmed eases.
It is imperative that you focus on both of these at the same time, or else thoughts will come back into play, cluttering your mind.
If the mind is calm, the body is calm.
Another one is to listen to background noises while also relaxing your gut.
Focus on both things at the same time for as long as you can. 15 seconds, 30 seconds, two minutes, it doesn't matter. Gradually increase the duration when you can and practice this throughout the day, or even at night so that you make it back to sleep.
As long as you pick two things to focus on at the same time, your mind will stop racing.
This practice literally saved me. Before, each day was extremely painful, and I thought I was going insane.
You can get through this. You can do it. Aim for small victories. Cherish the moments when your anxiety is relieved, however briefly. It gets better. Trust me. The external stimuli will bother you less and less as time passes.
If you have any questions, please don't hesitate to ask me. I learned many techniques from the therapist who I speak to online. He's quite good, and his focus is mindfulness.
Speaking to a professional may also be your preferred option. I'm just a regular guy who was going through something similar.
I hope this wasn't too much information to take in...
H