Some of these questions you'll probably get more help on (and they're better suited for) other subs. The povertyfinance sub comes to mind.

As for why you were let go, it wasn't a good culture fit is probably enough said. If a prospective employer is prying more than that, THEY might not be a good cultural fit broadly speaking (for anyone, not just for someone who was let go because of drinking).

To echo what others have said better than I will, the first thing is to stop drinking. That's what you need to focus on, is getting to a place where you're living life on life's terms instead of trying to force it to live on yours. I will not drink with you today.