I am sorry your EPI has had such a negative impact on your life! I am not aware of any link to Covid vaccines, but there’s so much we don’t know yet about the effects of both Coving infections and vaccination.
I am wondering if your lack of response to Creon is inadequate dosing. My understanding is that some people can require up to 15 caps a day: 3 with each meal and rwo with each snack. I am lucky in that 1 cap for lunch and dinner each controls my symptoms fairly well. Have you been checked for bile acid malabsorption? It’s possible that anoproblem coexists causing the diarrhea. It often occurs in people who have had gallbladder removed. The National pancreas foundation has good information on EPI and the dietary restrictions that help. I hope you get better control so your quality of life improves! It’s a learning process, sometimes lengthy, to manage this condition. A good dietitian might help as well. Hang in there and keep reading posts on EPI on this site. Experienced people with valuable information!

EPI can be idopathic, meaning there is no known cause for it. Many of us are in that situation. As for the life obstruction, I understand, most of us are in the same situation. Are you on any type of PERT, like ZENPEP or Creon? You need to stay in contact with your doctor and let him/her know you are still having problems. It often takes a while to get the dosage right, and even then you can still have issues despite taking enzymes. As you get to a better dosages, you will find that you have more good days than bad. However, you have to remember that this is not a medication to get rid of your symptoms, rather a replacement therapy for something your body no longer makes. Just as in the past, prior to having EPI, you can sometimes feel sick after a meal. It depends on how much fat, protein, sugar, etc. you put in your body. Each person is different, and their body will react differently to foods, than another person with EPI. I find that ginger tea and probiotics help to keep my gut feeling better. There is no miracle cure for this, it will take time and patience to figure out how to best deal with this.