I've been dealing with PCS for 3 years, with many similar symptoms to yours (extreme sensitivity to exertion and head bumps, light & sound sensitivity, brain fog, etc.). I've been receiving regular neurofeedback treatments for over 2 years, starting with LENS therapy and now NeurOptimal. They have both helped me immensely and I consider them worth every penny, and they have involved quite a lot of pennies.

That being said, neurofeedback has mainly only helped me with cognitive issues. I never felt "with it" after my first TBI almost a decade ago and the neurofeedback has helped tremendously with that and the cognitive fatigue. But I haven't found it to make me less vulnerable to setbacks from minor head bumps, overexertion, or overstimulation, and it's only helped a little with the headaches (though LENS did help more than NeurOptimal in that regard). It did pretty much cure my insomnia, LENS especially, which was a major boon. But beyond being able to sleep well, think more clearly, and generally be more aware of my surroundings, it hasn't done much in terms of functionality.

There have been 2 main interventions that HAVE helped me regain some functionality. The first is an anti-inflammatory/paleo diet, which has led to a major reduction in brain fog, headaches, and fatigue. And the second is physical therapy, which helped stabilize my neck (which before PT I didn't even realize was an issue) and got me back to the point of being able to tolerate moderate exercise (until I hit my head yet again a year and a half ago).

I too am relying on my parents for money right now (though I'm fortunate that they're quite supportive), so I know the feeling of having to pick and choose your treatments based on what someone else will consider worthwhile. And you may have a very different experience with any or all of these. But in my humble opinion, neurofeedback is absolutely amazing but given the limits of what it can do, the expense, and the logistical constraints in your situation, it's not the first treatment I'd try.

Good luck finding something that works for you. I'm happy to give more detail about my experience with neurofeedback if you have any questions.