Yeah, that's the ruff stuff with quitting it..
The shit hooks into Your brain's mood regulatory signaling system(s?)..
Either continue despite the negatives... or quit, and deal with that whole ordeal - if it get's bad, go talk to a doctor about it and get on mild antidepressants for a year or two.
Shouldn't be necessary though as long as You've got enough "natural joy" in life, or something like that.