If you look at how you posted your question, you've actually already split your information into three paragraphs by placing ellipses into the sentences. The first paragraph will act as the set-up, including the information about being consumed by the social aspects of high school. The end of your first paragraph should include a transition sentence to let the reader know this consumption lead to many different trials and hard times in your life.
Your second paragraph should include the information about your arrets, being jumped and robbed, and the fallout from this happening--having your hand broken, ruining your summer, and your unhappiness with the world and police. The end of this paragraph should have a transition sentence to let the reader know your essay will have a hopeful ending.
The third paragraph will include how things have turned around, like befriending the police officer, caught up in school, and become a student representative.