I feel physical pain from some noises, especially from modified vehicles

This could be a sensory processing disorder of some sort. Sensory processing disorders can cause issues with noise sensitivities, or light sensitivities or issues with texture etc. often people with ADHD, autism, both, or similar experience things like this.

But if it’s a new recent development that you haven’t always had and it’s becoming more disruptive to your life/causing more dysfunction it could be worth talking to a doctor (neurologist) about it.

Have you tried active noise canceling headphones? They'd be a cheap experiment and easily returnable if they don't help. I'm not as sensitive as you but I also dislike loud grumbling noises (especially cars and trucks and similar) and my Airpods Pro really help with that when I'm out for a walk. With or without music on, the combination of the silicon earplug and the electronic noise cancelation are pretty good at significantly decreasing (though not completely eliminating) mechanical noise.

For flickering lights, I wonder if polarized sunglasses can help decrease the total amount of light reaching your eyes, both directionally and in terms of wavelength? Might help turn a harsh white/blue spark into a gentle amber twinkle.

As for laws, some US localities have noise regulations (like CEQA, the California environmental law that measures noise impacts of new developments, among other impacts). In Canada there seems to be a similar Impact Assessment Act and also possible municipal regulations. Worth checking and asking: https://www.canada.ca/en/health-canada/services/noise-your-h...

May I suggest you find not just any doctor but an exceptional one, such as on the level of the late Oliver Sacks (a neurologist). Do not restrict yourself to location. Find and write to physicians who are at the top of their game. Given what you’re describing, you run a high risk of being painted into a corner by average doctors. That motion is already happening on this thread. I also definitely would not recommend an audiologist or other vocational health specialist. You need an intelligent and curious intellectual with deep domain knowledge.

You are not alone - there are definitely conditions that cause this, and noise sensitivity is a condition on its own.

I'm not going to attempt to get into the medical side of things, but I can recommend you look at something like this: https://us.loopearplugs.com/

I've had a pair of those for a while, and they help me. I've had them long enough that I don't remember exactly which brand/type they are... they literally just sit in my back pocket and I throw them in when I'm out somewhere loud.

All my life I have had introvert ears.

Ears that seem overly sensitive to all noise.

I must have perfect silence to fall to sleep, any odd noise wakes me up.

Supermarkets, Shopping centres, loud pubs and restaurants are no go areas for me.

My friends child is autistic and recommended to me:

Earloops.

I wear them all the time.

hearing hypersensitivity can be tested for, and characterized; you might then be able to hack noise cancelling headphones into more of a specific notch filter. an anti-hearing aid, in a way.

flicker sensitivity causes epileptic seizures in some susceptible folks, at some frequencies. There was some problems with particular anime shows setting off the audience some time ago. Again, this can be something you can test and characterize. At home, with a strobe light whose rate you can vary, if nothing else. Mitigation might be harder but at least you'd have a better idea what sets it off.

About sleep, maybe install windows with multi layers of glasses. In Canada we generally have tow layers of glasses on the windows for insulation. But I heard there are ones with 3.

You can also move to small towns if that's a viable solution. Downtown is usually busy and noisy.

Someone else already mentioned Autism and ADHD, possibly a combination. Those would be my first guesses. Another one is potentially migraines. They aren't always "a bad headache" as they tend to be portrayed but can run the gamut of symptoms. From nausea, to sound/light sensitivity, to temporary blindness, or actual pain.

Definitely sounds like something you'll want to investigate with a doc, assuming you have access to one. Biggest thing is if possible, shop around until you find someone who actually seems interested in what you're experiencing and doesn't dismiss your symptoms.

there are no efforts to mitigate noise pollution - acoustic ecologists have been writing about our world getting louder year by year, and in more and more remote places acoustic ecology is getting louder.

You may want to get checked out by an audiologist, and also see a doctor. Noise cancelling headphones can be dangerous (situational awareness, also pumping more dB's into your ears than you think you're being exposed to)

You might have misophonia.