Been there, done that!!!
The first time I left Canada to move to San Diego, I spent almost the entire time I lived there, pining for Canada, wanting to move back to Canada. The grass was definitely greener. DH finally accepted a job in Canada and even though my gut was saying "run away" my emotions obscured my judgement and 'getting back home' took priority over everything else. The job turned out to be a disaster. My gut was right (as always).
As well, there had been a lot of fundamental policy changes that had been implemented in Canada right before we left for San Diego and those changes had finally reared their ugly heads by the time we went back, it was awful. It was not the same country I had left. I HATED it. I too, felt like an alien in my own country. It didnt' help that many others saw what I was seeing as well.
We looked to get the hell out of there as soon as possible. And that is why I live in the UK now. In many ways, I wished I had never left the US.
The big lesson I learned in that process was to live your life where you live. Enjoy it, treasure it, and stop comparing. I'm much happier living with that philosophy.