Stocking Food

We have some food and a rudimentary storage system, but are totally unprepared for a true emergency. I guess I thought we were getting close to being ready, but I was only fooling myself.
When I took this picture, it really hit home that we need a real storage system immediately. First, I need to pull it all out onto the kitchen floor and resort everything. Then, I have to get a shelving system that will work with our food preservation methods. After all, food in ziploc bags needs different storage than canning jars or metal cans!
I also need to be able, somehow, to store enough food for four (4) people for 2-3 years. That will take some creativity as our pantry is about 4'x5'. And, of course, whatever I do must be done for free.
I'll let you know what I finally figure out!