I was diagnosed with ADHD around 7 months ago at age 16 and have been taking vyvanse, 40mg daily since then. The vyvanse has been working fine (actually, I suspect it may be at too low a dose and plan on asking to have it raised) but with a busy schedule such as mine, occasionally skips will happen. I have noticed the first day of taking vyvanse again after skipping a day I tend to feel drowsy, sick, spacey, etc, and coffee does not change anything. Although the next day it levels out and I feel fine. Are there any particular reasons this may be happening and what can I do to make myself feel better on these days?