Two thoughts come to mind.
1) The length of day is way longer (in my part of the U.S.). If that is the case for you, you are getting more seratonin from the longer daylight and even more if you are more active.
2) Is there any chance you switched from Wellbutrin to a time released or extended ?? Because the dosing may be different. That happened to a friend of mine and it really overmedicated him.
Let us know how you resolve this.
In His Grip,
UCTD (Undifferentiated Connective Tissue Disease), Hashimoto's, High BP, GI Inflamation, Diverticuloses
Plaquenil, RX Motrin, Lexapro, Amitriptylene, Salagen, Lotrel