Elana and Done-with-it give you some tough options. When I first got here, I would NOT have agreed with them... today, I do.
Addiction is progressive. My son started out as a runner. His addiction took him down to stealing from friends and family and then from local businesses to support "only" a pot habit.
In addition to the advice from above, I would urge you to get to some Alanon meetings as quickly as possible - and to attend at least 6 before deciding if they are right for you or not.
This is a difficult time in ANY mom's life - the point where our kids begin their first flight from the nest. Add in drug use and selling, and it became the worst time in my entire life (and that says something, believe me). Alanon saved my life, and then made it worth living again.
I wish you the best.