Welcome, hazelgirl, and I am sorry for the crisis in your life. Addiction always brings crisis.
Crisis can also be a turning point. But what I try to hold to, in my recovery from trying to save addicts from their crises, is that whether or not a crisis is actually a turning point is between the addict and God alone. The addict has his own life, he has free will, he has opportunity to heal if he chooses, and he has a relationship with a Higher Power which can be his source of comfort and direction if he so chooses.
I have a son, too, and I would be afraid and "a mess", just like you.
But if you know anything of addiction, if you speak to addicts in recovery, they will all tell you that what is happening to him (the chaos and misery) is a necessary stepping stone to recovery.
Many others here will be able to offer more support. Mostly I am concerned that you, as mother, will offer him safe harbor, and one thing I do know, that safe harbor will feed, not starve, his addictive disease.
AA is free, it is every day, and no matter where your son is now, he can find a meeting if he wants it.
Blessings to you and wishing you the very best outcome for all involved.