How do I get rid of my Social Anxiety?

Ive always been shy all my life. But I didnt realize I had Social Anxiety untill I reached my Freshman year in High School when I had to present my first project in front of the class. I remember that day my heart started beating really fast that it felt like the person next to me could hear it too that I asked my teacher if I could go to the bathroom. && when I did i started having a Panic Attack and looked at my chest in the mirror and saw red dots all over my chest. I knew those were my nerves acting up. I drank water hoping that would calm me down but of course it didnt. I got up and presented my project but my hands started shaking and I kept stuttering when I talked. I just wanted to die right there i was so embarrassed. I remember someone shouted in class "why are you shaking?" Worst day of my life. I didnt even want to show up to class the next day. I pretty much felt like shyt everytime I walked in that class after that day. I know that i dont have stage fright because Im a dancer and I dance infront of a lot of people. But when im public speaking or around a lot of people i get really bad anxiety. Ever since that day I dont present projects anymore. Sometimes i say i didnt do it and get a zero just because I didnt want to present infront of everyone. Untill my senior year. I started taking shots of alcohol before I had to present a project. Which really helped me a lot. I usually would take one or two just so I dont sound drunk when i present. So i know how to control myself. But now, I get invited to partys and stuff, when I hang out with people all i want to do is drink because it calms my nerves and i start talking a lot! & everyone loves talking to me and i get along with everyone. But when im sober im completly different. Im so shy and i dont like to talk a lot. I stay quiet. I wish i didnt have to drink to be social. Its also hard for me to find a job. My first job recently was waitressing at a diner. I quit after 3 weeks. I couldnt deal with people. & i was always nervous to go to work. I tried telling my mom a couple a times that I think i have a social anxiety problem. But she thinks its all stupid and she is always bugging me about getting a job. I keep telling her I am looking for a job where I dont have to deal or talk to a lot of people because im too shy. But she tells me that Im just lazy. Thats not even true at all. Theres so much I want to do in life but I cant do it because of my Social Anxiety. People say being put on Medication is the worst thing to do. And I know I cant depend on alcohol because I will just turn into an Alcoholic. And I would talk to a therapist but its actually hard for me to explain whats exactly wrong with me. I stopped going to college and started taking online classes because it feels like its getting worse and worse now that I am getting older. I dont like talking on the phone, I pretty much stay home a lot now. And i get very angry and depressed and stressed out about everything that Im starting to have anger problems. I punch walls, i yell at my family. This whole thing is ruining my life and I wish there was a way to get rid of my SAD. I cant talk to anyone about this & when I try they act like they understand but they really dont understand what im going thru. I have low self esteem because of this and I feel sad and lonely all the time. How can I get rid of SAD?