I'm so sorry to hear about your Dad. I lost my father very suddenly in August (he took his own life), so I can say with certainty that, even I'd you aren't aware of it, a shock like that will make your mind and body go all kinds of wacky. In the ensuing months, I have developed digestive problems and back and pelvic pain, which the HA beastie told me was ovarian cancer or colon cancer or any number of awful things. All my tests so far are normal, although I don't see the gastro until next month.
But what I noticed is that, when I was totally freaked out 24/7, I had diarrhea constantly. When I started seeing a psychiatrist and a counselor and got on the right medication, I started only having problems on and off. I still feel kinda funky, but I am starting to believe that alm the stress may have triggered irritable bowel syndrome. I read that 50% of people develop it after a stressful event. (In the past year, I have given birth, lost Dad, had Mom move in with us, and bought a house). So really, the whole year was one stressful event.
I am starting to feel better though, and I feel confident that you will too. Stick with the therapy and the exercise and meditation. Don't worry about the incidental stuff unless your doctors do. My abdominal ultrasound showed a hemangioma on my liver, which sounded scary to me, but my doctor just shrugged it off and said it was nothing, so I made myself take the same approach. Sure, there are awful stories on the Internet about doctors who miss something and someone suffers because of it, but that's not the norm. Most doctors are very good at their jobs. They had to go to school for a very long time. They want to help you. They don't want to get sued.
Good luck with your journey. I didn't know your Dad, so I am just guessing here, but I bet he would want you to be happy and really enjoy your life. I know mine would have.