is happiness more than just a state of mind?

Absolutely not, under the current model where Mind = Brain.

If Mind = Brain, then naturally your happiness is merely a perception. All perceptions of reality are configured and decoded by our brains, and therefore our perceptions of happiness are only manifestations within the mind.

Well, we are a part of the society!

The society has a common mind. Still, individuals think of having their own mind and proceed free in decisions and acts.

When one mind understands that, follows the best way to happiness, for the existing system!

To me, an emotion is simply a response to some outside stimulus that can be exhibit itself in both a physical an mental manner. Although the emotion is what we feel, it is always our decision what action we take based upon that emotion. As an example, judgmental people make me very sad, and although I think I would gain great happiness from kicking the tar out of them, I also know that it is wrong. Doing the right thing tends to make me MUCH happier.