I’m so sorry, what a lot to be going through!!
The “recommended” diet for someone with diabetes is not always the diet that works the best. Really, rice bread and pasta should be minimised or avoided altogether, whether brown or not, so don’t beat yourself up about not being able to eat brown rice and bread. You’d be better off not eating rice and bread at all.
A good diet for a type 2 diabetic is, usually, one that minimises carbohydrates (not just sugar). So - avoid potatoes, rice, bread, starchy vegetables, flour and of course sweets biscuits and cakes.
On the other hand, meat (both white and red meat), fish, shellfish, eggs, cheese, dairy, above ground veg (cooked is fine) butter and olive oil don’t generally raise blood sugar, so it can work well to mostly base your diet around these. Plenty of healthy natural fats, protein, dairy and a minimum of carbs