My father was a very gifted man, but, like many who fit that descriptor, he was a hopeless alcoholic for almost all of his life. The protection we had against his alcoholism was a comfortable upbringing, which if employed correctly covers almost traces of the problem publicly, but privately my mother endured a great deal despite having the foresight to recognise before many that my father's alcoholism was a disease state. An illness.
The definition of an addiction is when a habit evolves into something rathe more profound that causes mental, emotional or physical to the addict or to those around them. Having grown up with an alcoholic there can be a temptation to make the situation 'personal' - it is almost impossible not to do this, but it does not make the problem better for you or for them. Saying that they will "always be the same" or name-calling as some do, solves nothing. It merely takes attention away from the illness and focuses it on the individual's character instead. We would not do this to someone who had diabetes - a chronic illness, and it is almost always unhelpful to do the same with an addict.
If it is the case that alcoholism is the issue then that must be addressed as an illness. If you approached a doctor about it who knew their job, they would have compassion and understand how hard it was both for you and for the addict. To stand any chance of hope, the first step is to recognise that the addict is not able to control their addiction. They are responsible for wellness but they are not to blame for their illness. This might sound hokey, but for the last ten years of my father's life it was due to this approach that he found sobriety and finally enjoyed happiness with his family.
The personal has to removed from the equation. I apologise if it sounds trite, but underneath every addict is a desperate human with the normal range of human emotion who is often completely enslaved by their addiction. Alcohol causes physical dependence. If an alcoholic does not get a drink they will begin to withdraw. This partly explains some of the behaviour you have described. This does not even begin to factor in the psychological dependence which in many ways is more powerful. If your partner is an alcoholic he needs help and empathy not scorn and derision. I lived for seventeen years with an unpredictable, often frightening father, who's entire personality was twisted by alcohol - the illness of alcoholism.
The most critical question you must ask is - do you love this person enough to ride the storm? It was probably different in my situation as a daughter's love for his father is unconditional. But if you want him, and your relationship. If you want the possibility of happiness then it will take enormous amounts of courage on your part to firstly confront the situation with tact and sensitivity, and secondly, to help guide your partner back to the road of sobriety - and a possible chance at happiness again. It is possible. We only got ten years with my father but it was worth every moment and he would have been the first to shout that fact from the rooftops.
I hope I haven't sounded too blunt. Alcoholism is a living hell for partners, children and parents. But the worst kind of hell is experienced by the alcoholic themselves, who is forever seeking a dribble of happiness in the bottom of a glass.
Best wishes
Lettice Bonham Carter