I did read the story. Would PTSD or anxiety have caused his physical symptoms?
Going off his meds could have but more likely the anxiety meds kept his blood pressure low, masking an underlying physical issue which showed when he went off them and exercised.
In either case he required medical attention and evaluation. Like “what medications are you prescribed? And “are you still taking them? IOW, initial screening questions.
Since daddy didn’t immediately say his son had gone off to war and suffered PTSD and since I know the area and the counseling community the PatSD could have been that he got yelled at as a child
In addition to being off his medications, he might have been dehydrated or his blood sugar level might have dropped too low.