Weight problems.. Is anorexia the answer?

So.... Today my sister and brother had some neighborhood friends over. Their friends and them are each about 3 and 4 years older than me. I have recently gained some weight. My tummy and legs do look a little pudgy just cause I'm growing and stuff and weight gaining.I do feel really uncomfortable in my skin but usually with my fam I can be totally care free. We were all climbing a tree onto the roof. Then my brother starts saying stuff like "hey Kennedy you keep wiggling the tree." " And just get off now before you break it." Then my sister was like "yeah you just look soooo ugly today and i don't want the tree or the roof to break. K?" I think they were both just trying to look cool in front of their friends but whatever. Then my sister hit me on the back of the head and told me to get off. I was boiling with rage and just got off and went to my room and started crying. It made me feel really bad cause I feel fat all day long without their help. I feel like I need to lose like 20 lbs to be 110 lbs and that is the only way I will be happy I'm going into 8th and weigh 130 lbs 2 years ago I only weighed like 98ish. (between 5th and 6th) I want to be anorexic or only eat like 300 calories a day. I know it can hurt me but I look at some if he girls in my grade and feel their stick figure just crushing my sole. Can it really hurt me? Is it a bad idea? I just really need opinions.