I’m already addicted

I turned 21 two days ago and both days I’ve been drunk the entire day. Yah it’s my birthday so I can celebrate a little bit but it is hard for me stop. I am sitting in bed with the night sweats and horrible anxiety typing this from the alcohol withdrawal. I just don’t know if I will ever have the capacity to enjoy alcohol casually and it really sucks. I need to find a way to stop this before it gets too severe. I have had a 750ml vodka in two days how damaging is that? Please let me know. I think the only thing that is going to stop me is praying to God. Note this isn’t my first time being an alcoholic I was one my senior year in high school but it’s even worse now because I have unlimited access to it. I am a functional alcoholic and even after 8 drinks I appear sober. I am a very antisocial and awkward girl so this is why I feel the need to drink it helps me to socialize and relax. Advice please?