He has a problem. Some days he knows it, but most of the time the addiction that is beginning to take over tells him that he is normal - he is fine - there's nothing to be concerned about.
But you are concerned. You are here. You know the truth, and it is a difficult truth to know.
If it makes you feel any better, I've found that the period of time I spent questioning whether or not there really was a problem was the most painful and difficult portion of my recovery process.
You are not crazy or overreacting (though he may tell you that you are).
Stay strong. You are not alone. Focus on yourself and your children - I found focusing on the addict to be fruitless and frustrating.