Hey

I'm only 18 and still a student. I never had something like a holiday job or so, even though I really wished to have something like that. Social Anixiety makes it incredibly hard to stay integrated with society.
Still, I think that the problem with alcohol which you probably have can't be explained only through you trying to medicate your anxiety. I don't know about your situation but in my opinion, alcohol abuse doesn't require regular drinking, it can also mean that you lose control over usage paroxysmically, or when you drink out of the wrong reasons.
I sometimes have panic attacks and I regularly have anxiety symptoms in social situations, I know how nasty it feels.
I read a lot into it and therefore know that social anxiety increases the likelihood of alcohol abuse.
Still it sounds to me like a rationalisation and/or justification to say that getting so drunk you didn't care about getting fired anymore was only due to anxiety. I think there's probably a threshold where drinking to endure anxiety becomes drinking as a seperate gain of pleasure/addiction.
I think you should definitely consider seeking help for this before it gets out of hand! When you start to have an alcohol problem on top of your social anxiety, even if it's only occassional excessive drinking, you are on a very slippery pathway down to hell.
Hm, you mention you had medication for anxiety so I guess you're already familiar with psychiatrists.
I think for you, a therapist might be of more benefit. Therapists don't prescribe medication, they offer talk therapy. They can teach you relaxation methods to disengage and/or lessen anxiety when on stakes. With time, therapy can also reduce the thoughts and believes which lead to excessive anxiety.
I think there is a physical facet of anxiety, which is gidddiness, problems breathing and that stuff, and then there's the cognitive aspect behind it which is your thoughts and evaluation of your surrounding which cause the anxiety in the first place. So you can take as much medication as you want at a certain point, if you
believe there's a justified reason to be scared, you will suffer from fear, no matter if you try to fight it with chemicals.
Quiet a preach here, I hope you found some of it useful.

Sending thoughts of empathy and encouragement your way!