((( Melinda ))))
This is definetly a difficult situation. With the background you've mentioned, I would also be concerned that he is trying more than pot. Anxiety, rage etc, sounds just like me before I started using alcohol to cope. Once we get a substance in us, we get "hooked" on feeling good. He doesn't care about his asthma because right now, the pot is his solution.
I have found some links for you that might help:
Vermont Narcotics Anonymous
Drug Rehab in Vermont
Alanon is for families of the addict, and you would find help there as well:
Vermont Alanon
I wish you luck with your son. I hope he's able to get things under control at a young age. I know many people who got sober in their early teens, so it is possible. He has to hit his own bottom to realize he has a problem. Sometimes interventions are a way to make that happen.
Intervention information
Hope some of this helps. Keep posting and keep us updated.
~Rayna