Tell me how to protect our happiness?

Happiness comes and goes. It's not something we can simply hold on to. It's something we constantly strive to attain. There will be dark times, and that makes happiness even sweeter. Really, without the dark times coming in from time to time, happiness would mean nothing.
As for how to attain happiness, well we have to figure that out for ourselves.

Pro tip: Love and accept yourself. Surely you have flaws to work on, as do we all, but that shouldn't prevent the acceptance of who you are