Sometimes it just takes a really long time to get over certain people, even a year or two. It might be helpful to find something completely unrelated to self-improvement to absorb your mental energy.

Just as an analogy: the first few times I tried to quit smoking, I spent all of my time reading about quitting, talking to other people who were quitting,. This meant that I was ALWAYS thinking about smoking and sooner or later I'd start again. When I finally quit, I stayed away from the topic completely, until I got over the hump.