It sounds like you are going through an awful lot of fizzy drink, and possibly milk. Isn't this very expensive as well as producing lots of waste? You can't blame the supermarkets and manufacturers for you being very high consumers. Either cut down or get a soda stream.
YY to crushing bottles, also cut up or crush cardboard packaging so it takes up less space.
Check what your council accepts for recycling regularly as it does change. Are you sure they don't take plastic from bananas or the sofa? Ours take type 1, 2, 4 or 5 plastics, which accounts for most standard polythene type bags, bread bags (not Warburtons, but any that's soft, not crinkly) as well as mushroom cartons, yogurt pots and a lot else.
Or look at Terracycle, we actually set up a collection point in our garden for a certain type of waste, and now raise about £100 a year for charity just for collecting and parcelling this waste and having it collected, which Terracycle pay for.
On cucumbers, if they're not wrapped in plastic, they only last a couple of days, likewise mushrooms, so you're swapping plastic waste for food waste, so not necessarily any better. I've found that loose mushrooms in the supermarket are usually past their best before you even buy them,
But I do wonder about the poster who has two teen boys but doesn't get through bread before it goes off. Mumsnet led me to believe that the average teen boy ate several loaves of bread a week. But any bread that's being used for toast at least is fine in the freezer, and toast is a good way to use up slightly stale bread (also breadcrumbs for topping, coating or going in food like stuffing or meatballs).