Will my character be able to show signs of strength despite being in severe emotional distress due to PTSD?

I'm writing a novel and the main character, a veteran, has PTSD. But he has it under control. He begins the novel a pacifist, but since he is a journalist reporting in a very dangerous area, he is forced to kill someone to save his crew as the entire city breaks into chaos. This act brings him back to his traumatic experiences, and his PTSD spirals out of control, and he suffers from a severe emotional breakdown. But despite being under severe emotional distress, will he still show signs of strength as he has to find a way to bring his friends to safety? Or will he be so emotionally distraught that he won't?