Consumerism is:
-Owning a washing machine, instead of washing everything by hand in a tub with a crude homemade soap and then hanging it out to dry
-Having a house that is centrally heated, or cooled, instead of simply opening a window in the summer and having a fireplace in the winter (both of which are wholly inadequate to regulate the temperature of a large house)
-Taking a car from point A to point B, instead of walking (roughly 3 mph), taking a bike (10 mph), or taking a horse (15 mph)
-Owning a kitchen stove instead of gathering wood to make a fire, lit manually instead of with a match
-Being able to throw lukewarm food into a microwave to make it more palatable, and to reduce the risk of bacterial infection
-Being able to take a hot bath/shower every or almost every day
-Having indoor plumbing, and running water, enjoying the luxury of brushing your teeth twice a day with brand toothpaste and an industrial-grade toothbrush
-Having reliable metal tools (even if just pots, pans, and metal utensils), which probably could not be produced at home
-Buying your clothes at a store from a name brand instead of making it by hand or with a loom
-Owning ceramic plates and cups, washing these in a dishwasher instead of by hand with a homemade soap
-Wearing deodorant or antiperspirant
-Taking medicine when your stomach's upset
-Having a refrigerator/freezer so that you can wait several days/weeks/months to eat certain perishable foods, such as eggs, milk, or meat
-Being able to regularly apply a razor to your body, with shaving cream, and being able to apply a band-aid/antibiotics if you get a cut anywhere
Let's not kid ourselves: by world and historical standards we are obscenely wealthy, and the average guy here who talks crap about consumerism would not be willing to give half of these things up (and I didn't even mention entertainment like television, radio, internet, movies, or books). You might self-righteously believe that cutting back just a little bit will somehow make you not a rabid consumer, but in fact you still are, because that's just the nature of the society into which you were brought up and which you have always been a part of.
Sorry to break it to you.