

Occasionally you have to throw food that is spoiled. Not buying it in the first place is better. I’m very good at this, my gf is not. She eats half a corn cob, puts the rest in the fridge and two weeks later i have to throw it out after I find it grazing on the lettuce.
Most meat you can buy in bulk and split into smaller packages freeze If you have the freezer space. Vegetables are usually not cheaper in bulk here outside the occasional buy two for $X deal and they don’t survive the freezer as a rule.
You can tinker with what you eat. But it’s harder to do.
If you can stop eating candy and soft drinks that is probably the first I’d suggest. Zero nutritional value outside the sugar and a non zero cost.
Check what is most protein per $ in your area. Used to be ground beef here, but now it’s frozen chicken filet and the leaner cuts of pork.

Next time consider an orderly queue and a “please deposit DNA sample here” sign. Just in case the birth control acts up.