I (18 M) told my friend (18 M) to quit smoking weed for a bit to focus on his last year of high school. Initially I had told him on the bus ride home on a particularly heated afternoon and what I had said was "Yo (freinds name) you need to lay off the weed dude, you show up every day high as the clouds and it's affecting your grades" and to that he said (while visibility high) "yo, wachu mean?" And we go on a long tangent about the fact that he'll get caught eventually.
Not even a day later he gets caught with a pen inside of school and preceeds to get suspended for 3 days, after of Wich i repeat to him "you have to lay off the weed". Now when I tell you he's high, I mean he doesn't know where he is some mornings, it's concerning. I feel he's using it as a crutch and I'm concerned as to how far this will go before either he starts doing other things or he gets caught again.
Am I the asshole and is it my business or place as his friend to tell him in such a harsh manner to stop for a bit?