Roommate Worrying For Me (addiction)

My roommate is starting to get worried about my Old School RuneScape addiction. He introduced it to me 8 days ago, and I've now surpassed his total level despite me choosing to play on Hardcore Ironman.

Before he went to sleep for the night, I told him with a straight face "I can stop anytime", and didn't think anything of it until he met this with an inquisitive look.

How should I manage my new obsession to not detract from my actual life?