Well, you do have a bevy of symptoms there, don't you?
I have had gastritis before. It is brutally painful. Pain will definitely increase your blood pressure. When your blood pressure increases, you get anxious, which in turn increases your blood pressure
Gastritis is caused by stress. At least that's what I was told.
The sleep meds...did you go off them cold turkey?
The pain in your abdomen...was it excruciating, with profuse sweating and nausea? Intermittant pain, and then diarrhea?
The cortisol....do you have diabetes, using a corticosteroid for any reason?
The stress around Father's day, must have been pretty intense, to bring all this on......was it super bad?
The anxiety is the easiest part...people who have never been sick a day in their lives, and then have a "mystery illness" are very likely to become extremely anxious. The fact of not knowing what's wrong, along with never really going to hospitals, or Doctors, can freak anybody out.
I've given you more questions than answers, but it might be a number of things happening at the same time.