Addiction

Ok kind of a personal question here and I'm not sure where else to turn. Last night my husband and I were laying in bed and he asked if he could tell me something that he needed to tell me. I said yes. Well he goes on to tell me that he has watched porn since high school. Not consistently but often. Well he has de decided that he wants to quit but doesn't want any help. I ask him what I can do and I get it's my problem not yours. What do I do? He is everything to me and I didn't know that he did until last night. We have been married for three years but together seven. Never has he lost interest in me but I just don't want this to become a serious issue for us.