"Pilotboy, I enjoyed our conversation last night, but having had some quiet reflection time, I don't think we would be a good match. I wish you well on your journey!"
And do NOT read any mail he might reply with, or answer the phone.
People who are going to meetings that often (and it is probably more; the trend would be to average down), really need time to do the work on themselves. A DUI in Feb shows he still has a ways to go (he could have not only killed himself, but others around him).
DO NOT FEEL BAD about this!!! You have never met him - he is a grown-up - and life will go on.