Sounds similar to how I was in my twenties, lucky for you that your only half way through them. You can not waste the entirety of those years as you will realize later in life how precious those years are. I wasted the entirety of mine in a situation similar to you and regret it immensely.
First you need a plan to stop self medicating yourself with booze for your social anxieties. I know it is hard but there are many more productive ways to deal with it.
Start here, visit a Dr and be honest about your anxiety and alcohol consumption. Then start a plan, Dee has good links for you.