welcome and sorry you have to be here but at last you will find the support you need. My ex to whom I was married for 12 years and together for 16 was a very generous and kind soul. I knew he drank more than he probably should but he had a professional job that he was successful at and would never get drunk at functions. I learned that high functioning mostly means they are functioning for the outside world, at their job and with others, but really at home where they are comfortable they stop functioning, especially on an emotional level. They are very good at hiding it. No one knew my ex was an alcoholic, not even his grown child who lived with us for almost a year nor his youngest niece (who was 16 at the time) whom we raised. The last couple of years he would drink too much at a party from time to time but so do non alcoholics. Like other said, run for the hills. It will only get worse. My ex quit several times, once for 13 months. But he just white knuckled it and didn’t get treatment so he relapsed. So he may have stopped but recovery is so much more than just quitting. Most people can’t just quit without outside help. My ex did get clean but it came too late for me. Too much damage was done and I just really quit loving him. Had he done this 2 years prior we might ahve survived but the last 2 years did me in, he is still a good person and he did not want to divorce. But he has changed (he needed to in order to stay clean) and so did I (needed to be done with my codependence issue ). And I had too much resentment.
You have very little invested, you don’t live together, have no kids etc. Unless he truly seeks recovery he won’t stay clean more than likely and he found someone else because they don’t know him. As far as you thinking you know the real him....you don’t. You know the alcoholic him and you that he is an alcoholic. But that is where it stops. You have no idea what he would be like if he truly quit drinking. Overall my ex is a good person and kind, he just isn’t for me anymore. He is not the person I fell in love with.
You shouldn’t need therapy in order to be dating someone. If you need therapy before you are really in a committed long term relationship then that should be a red flag. I agree that therapy and alanon are probably still a very good idea for you, not to save this relationship but from you ending up in a similar codependent relationship (doesn’t even need to be with an addict, my friend is ina very codependent relationship and there are no substances involved, my first marriage was also like that so codependency does not necessarily mean you are involved with someone who is an addict).
I had weekly therapy for 2 years and a lot of that was me dealing with my codependent ways, it takes time to unlearn that as well.
Anyway, good luck with everything, keep coming back here, there is lots of good info.