He's reliving trauma over and over. A subconscious attempt at resolution via catharsis. Always failing. He should take shrooms prior to his next patrol. Probably achieve some kind of breakthrough. Get together with scarecrow.
Meditation, in a nutshell, is about manipulating and cultivating your attention (the buddhists call it "awareness"). Step 1 is finding a meditation technique that works for you. Experimentation may be necessary.
Here's my favorite meditation guide. It's short, clear and has nice pictures.
That the new genre. Check out "litrpg". Starts with discovery of "the system" (basically a machine god). Invariably leads to shopping and a new house.