I am 40 years old and just started Vyvanse 4 days ago, 30mg. My symptoms seem to be different from others. I feel great for the first 3-4 hours after taking git at 7am. Focused, motivated, relaxed, etc. But the I gradually start with a heavy head feeling with a slight headache and get sleepy. This worsens as the day goes on and by dinner time I can hardly stay awake and just have a hangover like feeling. I am sleeping better than I have in years though. Is this the "crash" i am hearing about? I almost feeli like I might need to take another 30mg mid day but havent tried because my dr has me scared about taking exactly as prescribed. Do you think this means I need a higher dose so the focused, motivated feeling lasts longer thean 4 hours?