Help! my life has went severley downhill

i used to be the happiest kid in the world. In middle school i was known as the ''cool'' kid and didnt even realize it. i was the best football player and was the strongest kid to ever go through. All the girls were attracted to me, and i just thought that everybody was nice. I wasnt stuckup and concieted like the people who are known as the cool kids. i was Nice to everybody and would do anything to help out a friend. I made it to highschool and was getting even more compliments. I didnt even know of the status of cool. I just thought everyone was nice. I continued getting better in football and wrestling, and was having colleges look at me for football and wrestling in just 9th grade. Senior girls were crazy over me and i was just a freshman. I also was extremley smart and made straight a's. I also enjoyed skateboarding and became sponsored at 13. I was beyond motivated and suceeded in everything. Then it all turned around my tenth grade year. My 9th grade summer i lifted weights everyday and gained alot of weight for football. I gained about 30 pounds, And everybody treated me different. I was made fun of and no longer got attention from all the girls. I realized i had to lose weight. Everyday consisted of ways i could lose weight. I no longer tried in anything else but that. My grades slipped and i quit doing sports. I started being called dumb everyday. I was called fat and ugly by everybody. And just a few months back i was known as the best looking guy in school. I started avoiding people and developed social anxiety disorder. I didnt even feel like a person anymore. I believed everything i was told and my self esteem got so bad, that i couldnt even look at my parents. I quit feeling emotion and lost myself as a person. I even developed social anxiety around my parents, for fear of them seeing what i turned into. I developed severe bulimia to where i would vomit up to ten times a day. My coaches even started calling me stupid and fat. Theyd make fun of me everyday. It became so bad i couldnt go out in public, because i just felt so worthless and ugly. I felt like anywhere i went people would stare at me because of how ugly i am. It continued through the rest of my highschool career but only got worse. Girls would come up to me and ask what happened to me. I felt like a social outcast and the ugliest person on earth. My obsession with losing weight got worse and thats all i thought about. I barley graduated and lost everything i could have accomplished. I now suffer with severe depression, social anxiety disorder, and bulimia. I have a horrible relationship with my parents because i cant even talk to them, for how low my self esteem is. I cant even go outside for fear of being around people. I hate for people to see what i am now, because of what i used to be. I drink everyday to numb it but i just end up crying. Im only 18 and have thrown away all my scholarships, friendships, relationships i have nothing. I want to get better so bad, but cant. My mom and dad are devistated and are going through depression because of what happened to me. I dont know what to do. I just want to be the person i used to be. The thing that hurts the most is i cant even talk to anybody about it because of how bad i feel about myself. I dont know how in a three month period i can go from who i was to girls and guys coming up to me saying what happened to you. your fat and ugly now. I feel like i have to get back down to my weight to even be accepted as a person. My bulimia continues to get worse but i never lose weight and my hair is starting to fall out. Please somebody Help me!! or tell me what i should do!!