PTSD is a life-long endeavor; there is no cure for it. The triggering traumatic event changes the landscape of the mind, it no longer works in the same fashion that it did before. The mind has been rewired; the neuropathways have been altered into a continuous loop. The PTSD triggering incident converts the fight or flight response in the primitive portion of our brain. Imagine having that scared feeling you get without the fear while keeping the bodily reactions; the tenseness, the adrenalin rush, the mind racing, heightened senses, and the hyper response reflex to react without thinking.
That is the mode of survival, now take out the danger part, you are safe. YOU KNOW you are safe, but that nagging sense that tells you "YOU ARE IN DANGER" for your life remains. You FEEL it in your bones, your rational mind says otherwise, but that does not take away the feeling that something is going to go wrong, terribly wrong. Imagine wanting to jump out of your skin, literally that's how it feels.
This can drive a person crazy; it does on a daily basis. Ok, now imagine that YOU DO NOT KNOW that you have this condition. Ok, now throw in the fear! Go out into the world and see how long it takes for you to find some trouble. See if you can properly discern an appropriate response in everyday situations, as regular social interactions have become a threat to you. You do not know why, but you just know it. Ok, throw in some denial, alright a bunch of denial. See if you don't end up divorced, incarcerated, homeless, unemployable, homicidal, suicidal or dead.
Right now writing about this is bringing it all to the forefront. Right now I am feeling all of these things. It is all racing around in my mind, a fevered pitch. I want to lock my door; it is open to let in some light in. But I have this obsession to go and lock it and shut it all out. Except that I know it will not lock out how I feel.
I have found that mediation helps considerably. If I close my eyes, concentrate on my breathing, imagining each part of my body is relaxing, I take my mind to every part of my body and relax it. Letting the tension go, to do just the opposite of what my body intelligence tells my mind. Let go, my mind does not command, it just imagines the letting go...I have a Buddha statue in my living room. I find that the image helps foster the feeling that I am looking for. Central to this is the breathing, slow deep breathing filling the upper part of the torso and the belly, and Belly breathing. When the body is relaxed go back to concentrating on the breathing. Do this long enough and with practice the mind will cease thoughts, suspending into everything and nothing.
Gotta go...from one extreme to another, that's my inner workings.
Hope this helped you understand what someone goes through with PTSD.