The human body can handle a lot of punishment but man, upwards of 500mg a day of Vyvanse? That is just crazy man. In the studies done on drug likability, at around 140-150 mg did Vyvanse equal or beat 40mg of d-amp IR. And you took 3 times this. Dude, tone in down. At some point drugs start losing their specificty for their targets and can bind and have effects in unwanted places. And amphetamines, even Vyvanse at high doses can cause major cardiac and cerebrovascular complications (read heart attack and stroke). Amp toxicity may be one of the most uncomfortable.
Ok enough of the lecture. First, please dont take any more stims for at least a week. Second, have a friend either with you or in close contact. Third, go to ER if you have really high heart rate, fever, coldness and numbness in the extremeties, chest pain, or slurred speech. Fourth, if you have a benzo, keep it close and take if needed. Hell take it now tbh. And last, you must stay hydrated, try to eat, and try to sleep.
I hope you are ok. Check back please.