Heart beats like a drum symptoms and conditions

I am inclined to disagree with almsot everything I have read so far. The first three days I was on Welbutrin XL, I was miserable. After 10 am, didn't want to do anything, not eat, not sleep, not be awake, not be alone, but not be around anyone..I was so miserable. After informing the doctor of this, he upped me to 300 mg. He said take 2 150 mg in the morning. Being that my problems were in the middle of the day, I decided to try my own experiment. I took one in the morning and one again at lunch. The result? Completely balanced out. Although I have only been on Wellbutrin XL for 2 weeks, I feel so much better. Big problem, though...if you skip a dose or run out before you pick up your prescription, everyone better stay away....FAR away! The rollercoaster is unbearable. I was lightheaded, vomitting, crying, had severe headaches...all because I went half a day without my medication.
On the positive side, I want to stay on it at least for a while. I keep a journal of my behavior everyday (good and bad) to see if I think I need an adjustment.
So far, I have lost 12 lbs in 2 weeks, have tons of energy, can focus well, have much confidence ( even wear makeup again), and am extremely calm. It is strange though that I am so calm, but my heart beats like a drum in a rock band! Go figure.