I'm 5'5 i used to weigh about 120, my bmi was normal then but on the low side, i now weigh about 108 and its underweight. i think it was the vyvanse that made me stop eating, but im not sure. it kind of freaks me out. i also have really terrible insomnia, last night i couldnt sleep until four a.m. and i woke up at 6a.m. thats typical for me, im really tired all the time, i think i might be anemic. would it be too much to start taking a sleeping medicine?