I can empathize with your feelings of being unable to commit to the things you value the most. I can get that way myself.
Sometimes it seems like because I'm not eating/wearing/consuming 100% organic/hand made/fairtrade everything, that I'm a bad person. I'm trying to get over the all or nothing mentality though. Each little thing that I can do to make the world a little better, or myself a little healthier is a good thing. It isn't all negated if I also occasionally shop for the cheapest price.
In the Summer and Fall eating local food is an easy way to do something nice for the environment and your body. In my area we've got some great farmers markets and tons of the produce now is organic. It's not even much more expensive than the supermarket alternatives (& some things are a lot cheaper) It's a good way to connect to what is seasonal for your area.