I weigh over 220 pounds and I am 16 years old

About 3 years ago or so I was skinny, but I was still ugly. I really do want to change that but I've tried 3 times. Now can I try but don't stop. At school I get bullied about my weight and my ugliness and I have been bullied my whole life that I believe them.How can I stop thinking about them and don't let it get in my head? My parents said I don't weight that much but, they do think I am fat but, they tell me I am not. I told my parents that I need to go to a therapist, but they think I am fine and I think they don't want to deal with it.