Chantix Dying of Cancer, Mood Disturbances, Clear as Day, Black Dog, Chanitx

I've taken Chantix twice now. I quit for two years the first time, but started smoking again so now I am on Chantix again. I am not smoking, and don't have any urges to smoke which is great. The Chanitx makes me feel pretty bad. I get headaches, nausea, and constipation. The dreams are pretty crazy but I actually enjoy them. Every once in a while I get easily agitated. Other than that I have never had any mood disturbances. I do have hallucinations which is the most concerning of the side effects. Yesterday I saw a black dog as clear as day in my living room and then it disappeared. We don't have a dog. I've had this happen three times, but different things. Because of this I am trying to avoid driving as much as possible. To me it's worth it to quit smoking, I think as bad as I feel now it's better than dying of cancer.