Dear BF anxiety~
Seeing someone you care about go off the rails is terribly upsetting, and I'm not at all surprised you react as you do when talking about this with him.
As you have said this freind of is a terrible influence, not only about the drugs, but by changing his behavior towards you. It's not surprising really, you stand for all that is sensible and caring.
I guess you have to face the fact your influence is limited, and that
at 17 he is - for right or wrong - making his own decisions.
Apart from yourself is there any one else your BF might listen too? If you ring our 24/7 Help Line on 1300 22 4636 they may be able to tell you what services in your area can be recommended, he really does need professional help, the hard part is to get him to realize there is a problem.
Frankly I'm concerned about you, facing the ongoing worry about your BF, and at the same time being treated badly when he is with his freind. Having panic attacks is pretty horrible and a sign you may need medical help to overcome all this anxiety
Can I suggest you see your GP in a long appointment and set out what you are feeling and how you are reacting?
Getting support can be a real help, but I don't just mean medical, are there others you can lean on? A family member or friend who will care and be there for you? Trying to face this in isolation is very hard