Hello,
(I'm not professional help, but rather a sufferer)
Though I haven't analogous wartime experiences to strictly compare, in my experience rooted in emotional abuse and neglect one can, with application to understanding the dynamic at play with P.T.S.D., look forward to a lessening of symptoms that are hitting you hard and with great persistence right at present. Such is the pain and core bewilderment felt that any conception of the future occupying a more placid psychological state by way of contrast seems a dream I'm sure. The following in short is what I can relate to you...
Sensitivity remains, circumstances that will prompt recall of horrors well-remembered but also buried via dissociation will always stand to be rekindled to 'catch you out', but the sheer intensity of the experience can subside in certain measure. There isn't any strict going back, but rather there will be imperfect pathways towards understanding and adaptation of what is now part of your lived experience. Professional psych. help can provide educated guidance and at the very least shouldn't disavow your experience (and harrowing re-experience) of much terrible. This said, the bulk of the work to be undertaken will be yours as you (and each of us in turn) struggles to coolly mesh cognitive understanding with hot emotional recall of the unbearable. Believe me, the hot emotional recall component of it will have the upper hand for some time even as you study much.
While there is no standard that can be strictly relied upon for each person and case is different, some speak of timelines in therapy of five to seven years. Sensitivity remain as related in the preceding paragraph, with the chief means to heal thyself is the improving capacity to sense a traumatic recollection coming on for circumstance and stressors that will set off triggers equating to felt suffering. In short - no cure, but ever-heightening awareness and perceptual resource development from within is what you can look forward to. I know it sucks, I can fully appreciate you desire 'a before', but at least what is scribbled above is honest. Kind regards...
M.