Introvert problem

I'm a 90's introvert and my girlfriend is 20's extrovert. Recently we got a fight. One week ago a new boy joined her team. Whenever i went to saw her i brought a chocolate 2 days ago i went to saw her and i brought a dairymilk and i gave to her. Suddenly that boy grabbed that dairymilk then he gaved back and he git her, I get anger and possessive. I informed her when i reached home i don't like he grabbed the dairymilk and he touched you. What i expected from her was "okay this won't happen again i won't let anyone touch me" but what happened was, she pick up a fight i won't speak with anyone see anyone I'm blocking everyone and try to live alone. I begged for hours to calm her at last she said please don't control me and please let me live with freedom. I know she purely love with me but the same time i don't like she hanging with boys. What i do, do i need to change or how to handle this situation?