Should be Poetry
I like the intensity of the conflict that you tackled--that being PTSD--but the way you wrote it sounds like the muse was telling you poetry and you were trying to write a story instead, and the two did not mix well together. Rather than reading like a story, it's a jumble of words that make no impression on the reader due to their placement, repetitive nature, and lack of ability to bring out the character. I can't keep track of what is going on--at all--and while one may make the excuse of that's how it feels to have PTSD, the talent in writing is writing a story that makes people feel and understand what it likes to have PTSD, rather than showing it.
Read the story now
As to the writing style, it is extremely passive and, although a lot of descriptive words are used, very tell rather than show. If you would get a handle on using the active voice, that will naturally make it easier for you to show rather than tell. Passive voice includes sentences where the subject is being acted upon and often uses words such as: were, was, and 'ing' verbs.
As to the telling not showing problem, here you are struggling to 'show' PTSD in a jumble of words, rather than telling a story. It is through stories that we as humans learn to understand things we have never experienced, as well as help us to understand that which we have. In order to help you audience really feel and understand what's going on, you need to first communicate in a way they can relate to. Make common ground. Maybe have one of your characters enjoying sparklers with a younger family member, far away enough from the big fireworks, and then some idiot college hoodlum let's off an illegal EXPLOSIVE firework somewhere nearby. Show how he reacts. SHOW how he feels. Show how the others feel.. Don't tell the audience what they're suppose to feel and see. Showing is much more powerful, and you need powerful.
Another suggestion is to chop this up, take up some of the bits that you think really hit home, and write it into a poem. Poems are the media you want to use for single word sentences and descriptions.
I hope that helps. ^.^