Hi mate.
Without wanting to sound disrespectful in any way... Thankyou for your post. You have reminded me why I must never drink alcohol again. I am age 23 and I can relate to what your saying exactly.
The only solution for me is to never touch a drink of alcohol again. I am 102 days sober today.
I have been where you are at 100's of times. The shame, worry, paranoia will only get worse as your behaviour/moods get more erratic. I am an alcoholic, you sound like you maybe an alcoholic to. I carried on drinking and in-order to avoid all of the worry,paranoia of what I might have said/done in a blackout I would just drink alone for the last 2 years, that way I wouldn't have quite the worry/paranoia of people seeing me. When I wasn't alowed to drink in my room no-more and I quite frankly felt too ashamed I would go and drink alone on park benches watching the world go by and just Thinking... about life, myself, and WTF has happened to myself. The booze was my best friend, my wingman, my comfort... apart from when I was running out it was my worst enemy and my demon who I would cry over just to "feel" that feeling again.
I suggest that you go to some AA meetings and just listen and take in the advice/philosophy that you can pick up from them, I don't follow AA religiously but go to meetings when i feel I need to but I have learned a lot from them and many of the philosophies used there really will help you.
It is not the stopping drinking which is the hard part but the staying off it.
I too was a Jekyl and hyde character; very shy and well-mannered/polite when sober but when drinking I became something else (I wouldn't really remember anyway as I was always too drunk but I wouldn't want to see my behaviour played back on Video!)
Get out whilst you still can and you've still something to get out for. It will only get worse. That's a guarantee.
All the best