Welcome, percy! Not being able to stop after starting is definitely a warning sign in my mind. And if you are bi-polar I can't imagine that drinking would be good for that.
I also used to just drink occasionally, but couldn't stop once I started. Problem is that over the years the time between those occasions got shorter and shorter.
How about quitting for 90 days? See where you're at after that? No slip ups, no exceptions for special occasions. Just no drinking whatsoever. Easy or difficult, it might give you a new perspective to simply distance yourself from the drink for a while.