I completely understand and applaud your decision to make sure your son has a safe and sane environment. I made the exact same decision for my own sons - when children are involved there really is no question whether you made the right decision.
I am just a couple of weeks into my own recovery from codependency and haven't been to an alanon meeting yet - but I have found a lot of help, support and guidance here and I am sure you will too. I have found a couple of meetings I can drive to - but I have to arrange for someone to look after the children while I go.