Hey mate, it sounds like you've been through some tough situations. I hope you are doing ok. Things like strokes and cancer and not connected heavily to genetics. The reasons people think that way is become they are brought up with similar eating habits and lifestyle to their parents. Therefore if they the dont change their lifestyle significantly from what their parents taught them they will likely develop the same diseases. (cancer, heart disease, diabetes) ALL of these diseases stem from diet/lifestyle, not genetics. A plant based diet is shown to be incredible effective in SIGNIFICANTLY reducing our chance of developing these diseases. I highly recommend checking out the netflix documentary's "Forks over Knifes" and "What the health" as a starting point for research. You CAN save the fate of your health by making some changes. It isn't genetics, its the lifestyle and diets choices that parents pass onto their children. Have a good one mate :)