I stumbled across the connection between diet and PTSD when I got back to the States, after being trafficked and tortured for several months in late 2013/early 2014. There are no support groups for men, but that's not a problem... it's something that you just learn to accept as part of the new "normal."
Another part of the new "normal" is that the foods and ingredients that you used to enjoy, no longer play nicely with your health. Before the incident, I was able to enjoy Splenda in my coffee, and hot dogs from the gas station. I could go out for pizza and eat the movie theater popcorn. And even though I'm not much of a bread person (aside from sweetbreads), I enjoyed pasta, rice, and baked-crust dinners.
Boy did that change. I had to change my diet completely, but I didn't have to quit eating anything. Sodas are still a no-go, but that's largely from the other artificial ingredients in them as much as the sweeteners. I'm an omnivore, and still am... but I went to a "clean" diet.
Essentially that means everything from scratch, as natural, original, and whole as possible. No artificial anything, and the list of trigger foods has grown longer, the more I've followed this regimen. It's a really tough diet, tougher than organic food, because it requires doing your own information research to understand why certain ingredients and foods have their effects.
I figured out I was sensitive to MSG in March 2016, after 22 years of doctors telling me it was all in my head. How? I Googled a description of the sickness.
In the past 3+ years, I've learned about healthier alternatives to the processed stuff most people use. For example: if you're reacting badly to all-purpose flour, it's the bleaching process. Try unbleached bread flour instead; it's more nutritious, is way less processed, and your baked goods are tastier and fuller. It also has more gluten, but the British brand "King Arthur" has less risk of glyphosate in it than Pilsbury or U.S. brands.
Many spice mixes and seasonings are actually pretty easy and better when made at home. Taco seasoning does not require whey or dairy, which are used to boost protein content. About 9 spices is all it takes, and you probably already have them in your kitchen.
One of my biggest surprises was finding out how unhealthy "organic" is. Even the USDA Certified is only 95% natural, except for salt and water. And "salt" can be stuff that isn't good for you, but is permitted. When you've got an organic food with multiple organic ingredients aren't required to list what's in each one, this is risky.
Things like that require not just due diligence, but making the time to sit down and do information research. Knowledge is the best food in managing your PTSD, because it can save you a lot of setbacks. Libraries are going to be one of your newest best friends, count on it. They're even better sources than Wikipedia, WebMD, or Dr. Bernard, because librarians are required to finish grad school to get the job.
I know this thread is about diet, but information research is crucial to the success of applying diet to your needs. I'm not a nutritionist or a doctor, I was an intern reference librarian for almost two years right after the 2008 crash. Take the advice with a huge block of salt, and consult with your medical professional for guidance.
I apologize for the TL;DR, but information research on blueberries led me here. Learning I'm not the only one dealing with this fight has done wonders for my soul.
May Fortune favor your Paths in the days ahead.