You would probably do better finding a few prepper sites for info. A year and a half until your doom scenario isn't much time to build up enough of a productive garden to support one person at the rate you're doing it. We have a good sized garden we've been growing in for 20 years and it was here 20 years before we bought the place. The wife has been using most of it to grow garlic for sale and has planted 3000 for next years crop. Most is sold before it's out of the ground. 14 different varieties this year.
Me out in my belly boat putting a screen filter on my water intake. Have to do that now to install a $160 air diffuser on the end of my aerator line or it's stinky water all winter. Hurt my back so hoping I can borrow my neighbour's little boat in a week or so before the ice gets too thick. Was ice to the shore but warmed up for a week and gave me space to get out there.
You know your probably right. But the land I'm on isn't conductive to soil gardening (had to buy a jackhammer) but I was gonna put some effort into it anyways. I figured I'd collect cardboard and leftovers from juiceland and use the rocks to make a huge soil bed. But its pretty daunting to shred all that cardboard, and then I didn't do something right and my experiment fails. That might put me behind! But my other plan is to harvest a few deer, enough for two years, but again that's something I have never done. Really though, I was heading down the prepper path even if it wasn't for the apocalypse... diy food is so much better than what I would normally eat, I imagine.
I've been catching rainwater for all of my cooking and drinking needs. I've done nothing to it except put some duck tape over the opening and use a britta filter. I've been able to get enough just between rainstorms so far, 50 gallons at a time. But I do have access to river water, which is about 50 feet below me. I ran about 400' of garden hose and fixed up a gas water pump to get it up here, to mix up aircrete or water the plants.
You should look into a cheap ozone generator used in cars on ebay. You probably could run it a few times a week to get rid of the smell. I bought one for about 10 dollars and it does indeed pump out some fury, so smell it at your own risk!