First day of Vyvanse/can i split a capsule?

Hi everyone, today was my first day taking Vyvanse (30mg) and i didn’t really feel any different, maybe just a slight change in appetite but that’s really it. i took it 6 hours ago if that explains anything. does anyone know if tomorrow might be different? has anyone had a similar experience? i’m also wondering that if i see no difference in the next week, can i somehow take half a capsule to make it 45? is this crazy to say pls lmk.