PTSD may vary more from one person to another than any other condition. It sure seems that way, from the cases I've known. That's why I think that you might be better served by asking this question of a professional familiar with trauma recovery, and who you've seen on at least several occasions. Often enough to get a feel for you, specifically, anyway. Because while resources like this forum, and other online resources, or texts are not only crucial, in my opinion..when it comes to asking for specific advice regarding how to address your unique set of symptoms...it's hard to know without knowing what yours look like, at least.
But that being said, I think johnnyboy had a lot of good tips. B vitamins, especially B4 (Panthotenic Acid), get eaten up by stress. But also B6 and B12, and folic acid....all of which are crucial to brain function...which, if it starts to flag...just makes everything more stressful, obviously.
Exercise, too, is crucial...even though it may well mean just boot-camping it out, and forcing yourself to do it despite it being almost impossible at first.
For me and most others who've had long term success, meaning progress, and diminishment of symptoms...meditation has been fundamental. But that's just another way of saying beginning to "open the floodgates", so to speak. In other words...one of the reasons people don't like silence, or sitting still, is...as johnnyboy put it..."sitting with your thoughts" is something to be avoided at all costs. But the problem is, that until we begin to do so, it's a stopgap measure at best...just fighting a losing battle at "blocking it out"...and it's then that it comes out sideways in unexpected moments, and damages relationships jobs, etc. So even though it's the last thing you want to do at the moment...getting to a place where you can just being to eek out a time to sit down and begin to experience those bad feelings/thoughts, and just think of it as therapeutic...like the pain of pulling a bad tooth...getting to that place is necessary to real eventual recovery. Because anything else is just going to be a bandaid, at best, and not lead to improvement in the long run. There's also a lot of work being done on "somatic reexperiencing"...exercises designed to help you "release the trauma". One book on the subject is "Waking the Tiger", by Levine.
Another approach is medication...specifically alpha and beta adrenergic inhibitors/agonist...Clonidine, Guanfiacine, Inderal, most often. These can help reduce your sensitivity to stress/adrenaline so that you at least have a moment to stop yourself, before just lashing out, etc., and just result in less of an overall sense that you're walking around like a powder keg, waiting to go off.
I agree that therapy of some kind...as in guidance by a professional...is likely to be necessary for any real long-term reduction in symptoms. But more and more research is showing that traditional forms of "talk therapy" aren't necessarily as beneficial to recovery from trauma symptoms as other varieties...ie somatic reexperiencing, exposure therapy, EMDR, and the list goes on. Many now say that the "talk therapy" of verbally rehashing your abuse can actually tend to be counterproductive in that it's re-traumatizing...but that depends on the case, of course.
Be very careful, though, and check out the references of any counselor whose help you seek...as the numbers of people harmed rather than helped by therapists is notoriously huge....and many therapists lament the necessity of first undoing the trauma inflicted by previous therapists...before they can even make a start.
And give yourself a break. I know that's one of the biggest sources of stress for me, as well as many others I've known with similar issues...we stress ourselves out over not being able to deal with stress better. How productive is that? Right? Don't be your own worst enemy. You need at least yourself on your side if you're going to get through this...and with that in mind...monitor your self-talk...and other habits/reactions, regularly...have the urge to just through a burrito in the microwave instead of preparing a healthy well balanced meal?....Give your unhealthy self a time out...tap her on the shoulder, and say..."Hey...none of that. You're worth more than that. You know you should be taking better care of yourself. Now get with it". Start talking to yourself as you would a friend, instead of how you'd imagine an enemy would talk to you. When I started to wake up to what I was directing at myself with my own head...it was like "hey...who is this a**hole, anyway? Shut up, already!" Prior to that...I'd just accepted it like it was some kind of subliminal programming being played at such a low volume that I wasn't consciously aware of it...and without knowing it...it had become a kind of theme music for my life. And what kind of movie is THAT going to be...with theme music like that? No wonder I was miserable. Imagine watching a Disney cartoon with horror movie theme music...something bad playing in the background will ruin what you're seeing, no matter how good it is.
Sleep is crucial, too, and if your nightmares are too bad for you to be able to get good sleep regularly...then I recommend Prazosin, which has been found to be very successful in reducing PTSD related nightmares.
And do the obvious things. Get some plants...green causes the human nervous system to relax. Get a kitten. Get a scented candle you like. Clean up regularly...it's meditative, and a cluttered or dirty house usually is more responsible for feelings of guilt and discomfort than we realize. Take a long hot bath. I know that when I'm in one of those "holes"...I think it's pointless to do anything whatsoever...and that maybe if I just lie there, it will go away...which only makes it worse.
Feel free to PM me, and good luck