Maybe talk to your doctor and see if you can put your child on a smaller dose or on a different medication. There’s also the option of looking into getting an educational therapist. Your child is still young so I think the latter would benefit him.
I would also mention that it would be a good idea to look into schools that specialize in children’s disabilities. The only problem is that those tend to be expensive, so a good amount of research is important.
Best of luck to you. I hated Vyvanse.