Boggled:
Welcome to SR and we thank God that you have reached a point where you're willing to learn from the wisdom of others.
Regarding your questions - they are valid ones that do need to be addressed. But before you do that, start with Naranon and Alanon meetings in order to find your footing. To back off from enabling behaviors takes a lot of strength which you will gain from going to those meetings - and your questions about how to deal with you son, well you will find the answer to those questions as you go...
Oh, and don't forget to come back here where others can share their experience, strength, and hope (ESH) with you. we've been where you're at and can hopefully guide you on your journey. Before you know it, you will have ESH that you can share with others!!