The question of many who are involved with an addict. I used to think my father didn't love me because he was always drunk, making promises, forgetting everything and basically being horrid. My Mom, his drinking buddy of sorts, was completely overwhelmed with 5 kids and 'managing' the addiction. So no Mom either. Addiction affects the whole family and everyone seems to play their role.
You don't have to treat addiction as a disease. I think that term is used because if left untreated it progresses in the same way a disease does. And recovery is really just remission. The addiction is still there, but it is being treated.
Sooo what to do? Take care of yourself and the kids. Get educated and get help. Al anon etc. Al anon can seem weird at first because it asks you, the apparent victim, to take care of your side of the condition. As if you have a problem. But often the spouse, child, friend, parent etc of the addict are part of the progression of the addiction. The enabler, the codie for example.
You can't change him. You can only protect you and clearly communicate your needs and intentions. The rest is up to him.