My girlfriend want's to change the way I see the live, she's keep telling me that I don't relax, but I believe that is wrong because I see things in a most mature way, I think, All I want from my live is be in peace with all the people that are close to me. She is making exactly the opposite and is making my live as hard as it could be.

What could I do to make her understand that is not the way to have a good relation ship?

Firstly its your life not live :)

Secondly you can't change no one, only you can change you!
Communicate together about this issue, talk to her.

You two need some honest talking about what you want from this relationship. No communication, no relatinship! A relationship is about two people working together to the benefit of you both. Talk and listen. It takes time and work from you both.