People bully me and it really hurts

Hi! I’m an 11 year old boy. So, the thing is I am pretty “fat” and that is what I get bullied for. Thing is, these three dudes, let’s call them Michael,Andrew and Valentine. These are the three problems that destroyed my life. So, Michael calls my mother an “easy woman” and he says that I am an idiot, a retard, an obese bastard, etc. I wish that I could say “Whatever, I don’t care!” and then punch him in the face, but he just keeps saying these things and once he comes up with something, he says it to me, then to my friends and then the entire school! This idiot ruined my life and I can’t go to sleep thanks to his stupid words. Every time I tell my parents about this, they say ignore him, ignore him! But, it’s impossible knowing that I have to go through this every single day! Thing is, he is the worst bully to deal with, because 90% of the teachers that know him think he is the “Perfect little angel that never does anything”. This Valentine dude calls me a Walking pig and the Andrew dude says that I have “male breasts” . Even the 6th graders are picking on me too! They say I am the continent of Asia, etc. I wanted to kill my self in the 4th grade thanks to these people! Thank god that I recently managed to convince Andrew and Valentine to stop, but Michael keeps bullying. Yesterday I slapped him and said if he does not stop, I will tell everybody who he really is. But he doesn’t stop. If he continues today, I will do exactly as I said.