Welcome, triplejs - I'm sorry to hear about your son, but glad that he's not drinking or using and that he seems to be more interested in his recovery this time. As they say in AA "it takes what it takes." Denial is such a huge part of any kind of addiction - it's really good that he's admitted his problem.
I can only imagine (as a mother) what you must have gone through and the worry you have. If Al-Anon doesn't work for you, have you ever considered counseling? I'm sure you'll find lots of understanding and support here, too. Prayers for your family......