ADHD kids-How did they do their first semester/first year?

My S2 is in his 2nd semester of his first year. He managed to pass 1 out of 4 classes in the fall with a D. He takes zoloft and concerta for ADHD and anxiety. He did try and turn things around at the end of the fall semester but it was to little to late. He barely went to class in the fall for the first 6 weeks and handed in nothing in. This semester he is on academic probation and must get a 2.6 across the board to be able to go back in the fall. This semester seemed to get off to a good start. He has been attending classes for the most part, 90% of the time. He is struggling with his organization, which has always been a huge issue. He is now struggling with friendships and his anxiety. He has now also gotten in trouble for alcohol and weed and is on probation for that. I think they might ask him to leave. I feel so bad for him and I want to strangle him and I want to cry for him. He barely got out of high school with a 73 GPA but really wanted to go to college. S1 is in his 3rd year of college and S3 is a sophmore in HS neither have ADHD. S2 is depressed and anxious and I don’t know what to do. We need to find him a new Dr. too. Help please all advice accepted LOL