Please, please do not bring a child into the picture..........it will change nothing for him, only for you and the child......read the posts of others here that have children and know that your husband is no different....the only thing that will change him is him and only if he truly wants to change and is willing to do the hard work......
So he used on your anniversary, well he will use when a child is born, on it's birthday and any other time he wants to.....because it is and will remain all about him......change for yourself is all that you can do, think about your life and your future.....I know this sounds harsh and I wish it was different...but addiction is harsh.....take care of yourself...