Social anxiety ?! Plz help

So I was in an abusive relationship for 5 years. My ex would not let me leave his sight and had me cut off all my friends. Every single one of them. I was only allowed to hang out with him and his friends.. and even then I wouldn’t be allowed to talk to them at all. Like they would try to talk to me and if I answered once I got I would get yelled at and accused of being a whore. So I literally wouldn’t talk to anyone.. just be on my phone in my own world. Before any of ya’ll judge I was 16 when I met my ex and felt stuck. It was a horrible feeling but now 21 I finally got out a few months ago. I’m seeing this guy I previously was really close with high school. He’s really sweet and we see each other almost every weekend.. anyways lately he’s been inviting me over to drink w him and his guy friends and occasionally girls of his guy friends. I am so terrified of socializing and keep flaking.. even tho I partially know some of them from high school too. I’m not sure what I’m “afraid” of. I just feel awkward going and over think what I should say or do. When I’m pushed in the moment I feel fine after a while but for some reason I feel really intimidated when talking to other girls.. just because I don’t know how to talk to them or make friends anymore. I never had this problem until I got w my ex and I hate myself so much for it. I only have one friend which is my best friend all the way through middle-HS but she’s busy most weekends w work and school. Can anybody give me tips on how to push myself to go? I know that I will feel fine once I’m drunk.. it’s just initially meeting people and being asked a thousand questions or having the spotlight completely on me. I have so many fears.. even eating in front of people because my ex would always yell at me for “eating too loud” even tho I don’t even eat w my mouth open.. which I’ve gotten comfortable around my friend because I pushed myself to go out to eat w him. I just need major help w this. I wish there was some type of pill I could take to cure this. I feel like a straight LOSER.