Some prick I've known for a long time who is in my form was backhanding my arm all the time. You know after a while it starts fucking hurting. So I gripped two legs of his chair and flipped it over. He went "CMON EN FUCKING TRY IT AGAIN". I pushed him and told him to fuck off. I'm not v good at fighting so here comes the bad part. He went to swing for me to I clinched with him he pushed my head down tried to punch me in the nose area, I blocked pretty much every punch but then I pushed him off and he swung like twwo right hands caught me in the side of the face. I now have like 3 bruises on the side of my face. I went to the main office and said that I tripped down the last step of the stairs and banged my face on the metal bar of a door. I told my mother the same and is suspicious about it. What should I do?