I haven't gone to quite the extreme that you have, but I'm getting started.
I built a raised bed this spring and planted more than I needed (tomatoes, peppers, lima beans, and corn) – I'm freezing and canning the surplus for later use.
I intend to add another raised bed (or 2) next spring.
I've also bought some vegetables and fruit at local fruit stands while they are in season and have frozen that for later use.
I got a great deal on a huge basket of peaches – ate a few, froze some and made several jars of peach jam.
I've put the word out locally – I'll accept anyone's surplus produce. You would be surprised how many people give away tomatoes, zucchini, corn, etc. because they have too much and don't want to go to the trouble of preserving it.
Every little bit helps!