My man of over 4 years just told me he has a p*rn addiction. I had no idea. Thoughts?

I would have never expected it be an addiction at all, and I am shocked to find this information out. It isn’t like he can’t function, he holds a stable job and everything he just uses porn “multiple times a week”. He wants to change. I obviously feel quite heavy hearing this information. Anyone have any experience with this? Of course I am grateful he had the nerve to tell me as I think many men go decades in marriages etc. without sharing it. We’re both in our late 20s, just got a house together. Thoughts?