\\\"An 18 year old army recruit wakes up in modern time from a Vietnam era secret experiment set in Puerto Rico, that intended to train soldiers via Virtual Reality. He now suffers from distorted perception and PTSD, which introduces him in a quixotic journey trying to find reality and prove his experience, against US Army attempts to dissuade him.\\\"

Thanks for the feedback. I agree on the similarities with Jacob's Ladder, so I guess I'm rethinking the goal.

I think timmyelliot is right, there is a bunch of tweaking that needs to happen here.
Go back to basics, break it down to the elements:
Who is your flawed protagonist? A disoriented soldier?
What is the event? Waking up from a 30-odd year sleep?
What is the goal? To expose the military's secret experiments on its own soldiers? (this goal isn't particularly compelling to me. I think if perhaps he wanted to shut down the experiment, I get more of a sense of how exciting the story could be, but as it is my thoughts are ... so what, he goes and has an interview with a journalist and then that's the end of the story?)
Who is the antagonist - this story would probably work well if you had a specific character representing the military who wants to catch your protagonist.
What are the stakes of failure? The military will kill him?

So the story is:

"After waking up from a 30 year sleep, a disoriented private fights to expose his country's secret experiments on their own soldiers against a maniacal general intent on silencing him for good."

The fact that the guy has been asleep since the Vietnam war, and is still only 18, is confusing and maybe best left for the actual script.
I think the PTSD and distorted perception are certainly obstacles for him to overcome, but don't really factor into the overarching goal.

I believe it is hyphenated, like this "18-year-old." I like the ideas. I know you have an idea for an original story, but the logline needs a more tweaking. To me, it comes across as a Jacob's Ladder knock-off.