I Recently Switched From Adderall 15 Mg, Twice A Day

I recently switched from Adderall 15 mg, twice a day to vyvanse 30 mg. once a day. I have been extremely drowsy and I noticed all of my adhd symptoms coming back. I have increased my coffee intake just to make it through my day. This has been happening for approximately 8 days. I contacted my psychiatrist and she prescribed me 40 mg of vyvanse. I have yet to take the new pills. Today I have noticed very sharp kidney pains on both sides of my lower back. Is this caused by the vyvanse or the coffee intake?