witchx.....we are not usually told (warned) that the usual ways of dealing with relationships...with normal, stabilized, reasonable people....are turned topsy turvy with addicts and alcoholics.
The dating period is to determine who would be a good fit for you....
It is o.k. to decide to end it....whether he agrees with your decision or not.
Your welfare is your first responsibility.....
You have every right to just end it. You don't have to go a step further....
His life...his decisions, and their consequences are his responsibility.....
I suggest that you send him a message (write a letter, if you must)....and simply say that this is not working for you...it is not a good fit...and, you wish him the best.
Anything further with him is inviting a world of pain and hurt into your future, I think.....