I'm taking 30xr adderall (dextroamphetamine and racemic amphetamine) twice a day and it's not lasting as long. i feel like i need 3 a day to last me through the day. but isn't that a lot.

Yes: Yes, that is a fairly high dose ... But, it's very likely that your system has accommodated to the racemic mixture that comprises Adderall. I'd suggest talking to your doctor about switching to Vyvanse (lisdexamfetamine). It has a longer duration of action than Adderall XR and in the same chemical class. I've had good results with this solution with my patients - Hope that it helps!