I have it in my family too - several close relations experiencing it in their late 40s onwards, over multiple generations.
As I understand it, there is a fair amount of data to show that metabolic syndrome is a huge problem with both breast and bowel cancer. This abstract sums is up: Metabolic syndrome, hyperinsulinemia, and col... [Am J Clin Nutr. 2007] - PubMed - NCBI (Lots of stuff in google scholar if you look up hyperinsulinemea and cancer.)
From this point of view (i.e. there are other competing points of view!), diet and lifestyle tweaks should aim to develop and maintain insulin sensitivity. (Poor sleep and stress both contribute to insulin resistance, even if diet is well balanced.)
'Meat = cancer' research is always overloaded with confounding factors - omnivores are more likely to smoke, drink booze, not exercise, etc. Food quality is not factored in (e.g. grainfed vs grassfed beef) and other potentially problematic foods, like gluten and sugar are often not factored in at all (or factored wrongly - Robb Wolf mentioned one study where a pepperoni pizza counted was a serving of meat. Regardless of whether one eats pepperoni pizza, it is undeniable that is is completely different nutritionally to a steak!)
Apologies - I have no comment on your diet or your current issues.