The Western world has invented too much of self-awareness and social reflection. People smile too much, smile at strangers, worry about social acceptance, worry about self, go crazy about all thing cosmetic in life and at work.
You don't need to think too much about anything or have too much of self-awareness. Just be real, with neutral expression, relaxed, not emotional etc.
The worst thing is having happiness as a goal. It should be a side-effect, not a goal. Infact, you shouldn't have any goals. Any incremental achievement is nice to have, and down-side is business as usual. Just deal with it.
You get angry or emotional because reality is too different from your expectations. That's the fault of your expectations, not of reality.