I send my good thoughts to you dubs, something such as that experience is difficult to come to terms with, but if i can pass anthing to you it is to release the guilt by truly going through the healing process, as just on what i have read, it seems you were unable to do so and instead kind of just sucked it up and put on a stiff upper lip,
You cannot halt such a process without some kickback, and the guilt is adding to it but seems to be also masking the anger stage you were stuck in via the healing process, if you can come to understand that we each have a destiny, no matter how long or short, and nothing prevents that coming to each of us, it will help you alleviate the blame you are punishing yourself with, this can then allow you to move from anger to acceptance as part of your healing,
the first stage is disbelief which im sure you have experienced at the time, anger follows usually, so be kinder to yourself and not beat yourself up over this, as destiny cannot be denied, then you can move to acceptance which will help you grow....guilt is a bag of bricks that serves no purpose but to harm those who carry it.....
Ptsd is certainly something that such a experience would cause, but the acceptance of destiny and the fact you have clearly more to do in life before yours ends is something for you to consider more than looking behind you and crippling any chance of fulfilling that healing process , life can turn on a penny dubs...if you let go of the guilt and heal yourself fully firstly, you do not know just how your life can change for the better, dont write yourself off just yet....
I say this in the best way i can to you, and i do it heartfelt as i know it is possible to overcome such circumstances, you can do it, but with all the advice in the world, only you can walk that path and do it....best wishes to you.