The B12 and fish oil are a good start. Folate and B6 is also worth adding. It takes months for vitamin and mineral supplementation to show a difference. The biggest difference will be strengthening your tolerance of stress and moderating your mood,personality.
You can get you B12 and folate tested with a blood test. You want to be near 1000 pg/mL of B12. (picograms per milliliter)
I have been on a supplement regimen since a doctor started me on it in 1982. My wife can tell when I have skipped a few days by changes in my personality and mood.
A B100 complex each day plus 100 mgs of B12 and 100 mgs of B6 is about my level of B's. The compromised brain needs B's.
The melatonin is not a help to many. The magnesium should be part of a full spectrum of minerals.
Think of supplement nutrition like going to the range. If you miss a few times at the range, you don't notice. If you miss a few months at the range, the difference become obvious.
Supplements need to first help the brain detoxify from the byproducts of the trauma. Then, they can start to help you brain strengthen and rebuild.
The range issue is one of cumulative very minor impacts. Subconcussive impacts are the biggest problem for those of us with Multiple Impact Syndrome. Our brains are so much more sensitive to any jarring of the brain. The ear plugs and head phones is a good idea. I do the same when I go shooting.
Before you talk about your PCS, it will be good for you to gain some strong background understanding of concussion. The TBI Survival Guide is a good start. Download it at
www.tbiguide.com
The YouTube video series by John Byler at
http://www.youtube.com/watch?v=x9Xso4qGdlI would be a good start for your fellow officers.
Your department should make it a part of recurrent training. This past week's episode of Harry's Law also did a good job of explaining mTBI and concussion.
Next time you are at the range, put your hand against the divider separating shooters. Unless it is a brick or concrete wall, you can feel the impact of the shots fired on the other side. This impact is hitting your brain. This is similar to the blast concussions suffered by soldiers in Iraq except much less intense.
You sound like you have some better than normal doctors helping you. You are fortunate.
My best to you.