Your roommate may be freaking out at your symptoms and upset at you for going this far in your drinking, and completely unable to understand why you don't just stop. Your continued drinking makes no sense to him and seems beyond insane.
Why not have a talk with him to explain why you must keep getting drunk until a detox seperates you from the booze for a few days. The earlier you get looked at the better. It could be a long 3 weeks if you don't act sooner and once we start bleeding things can go south in a hurry.
A bit ironic when we fear dying from detox so much that we keep drinking and cause ourselves to die from hemmoraging or organ failure. But then, drinking and fear often go together, one supporting, reinforcing and intensifying the other.
What plans have you after detox? Staying stopped might be far, far more difficult than just stopping, as difficult as that is currently for you.