*deep breathe* Okay. This one might sound a little weird so bear with me, please.
So, this story I'm planning to write is set in a superhero universe, where the characters have superpowers like flight, telepathy, pyrokinesis and so on. No, it wont be set in the DC or Marvel universe. I'm taking characters from a debatably-normal universe and giving them powers.
A little backstory:
The focus character, a boy at the age of 8 ( or 10. still haven't decided. ) went on a fishing trip with his father and grandfather ( his mother died years prior ). The boat was attacked by sharks, his father and grandfather died, and he was left at the boat for 6 to 8 hours before he was rescued. Needless to say, he was left with a case of PTSD and Anxiety Disorder. He is then taken from one orphanage to another, not receiving the help needed for someone of his condition, ( or rather, refusing to acknowledge said condition ) until he reaches the age of 13, when he manifests superpowers. This is the tricky part. His power is to turn into half-shark. With the sight, smell, electroreception and sonar senses of a shark, along with fangs and scales and a constant reminder of his traumatic experience.
So here's my question: What are the most realistic reactions, long term coping mechanisms and psychological injuries for someone in this situation? I've done all the research I can with the resources I have on PTSD, and all I found where ways to recover. no explanation of how wrong it could go when left untreated. I don't have any personal experience in this field, and I don't want to offend anyone with PTSD or undermine their struggle by getting anything wrong.
So... Help? This is the first time I ask a question here, sorry if it's a little jumbled up or all over the place!