My 15 yr old son just started meds 4 months ago. He managed to make good grades in grade school but high school hit him like a ton of bricks. He is not hyper--he just doesn't have the attention span. He started meds but he also has a teacher's advocate at school who not only checks on all his homework assignments, but she meets with him to discuss how HE thinks things are going. together, they work on different approaches to organization. (Teenagers seem to think their parents are dumb so she has been a godsend.)
At first he was mad at us. He did not want to meet with his advocate, thought we thought he was "dumb". My dh and I decided he must be a genius. For a kid who took NO NOTES for an entire semester, what he learned, he learned by sight/sound. He cannot process listening to a teacher, watching it get written on the board and then take all that stimuli in, and produce something on paper.
Organization for him is still frustrating. He has not come up with a system yet to keep him on track. Writing papers is also VERY very hard for him and we are really working with him to find what makes sense to him.
He is on Vyvance. He has lost 10 lbs and we are pushing calories/shakes. He has no appetite. The meds have helped him in our eyes. He can carry on a conversation and seems to know what homework he has and how he's going to start things. I think it has been a good thing. We saw many signs, we just never connected the dots. I wish we had been able to intervene earlier. His self-esteem took a beating. he is positive these days and I think if we gave him the choice, to stop the meds, he would not do it.
HTH, hang in there.