Chantix Rapid Weight Gain, Last Cigarette, Anti Depressants, Panic Attacks, Energy Level

I used Chantix to stop a 2.5 pk a day habit. I started taking Chantix in August of 08. Smoked my last cigarette Sept 08 and have not resumed the habit.
I am still suffering the joint aches and pain especially in my feet and legs, I had rapid weight gain that came on rapidly...although I was heavily into exercise and Zumba...my size 6 ballooned to a size 12 in 12 months...I could no longer go to exercise because I lost all of my energy level and was very tired...and moody..I went to the doctor with a list of symptoms and he decided that I need a low dose of anti-depressants...which I never took, because I felt it had to be something else. I switched Doctors and was told that no side effects of Chantix was heard of by him...I still after 20 months of being off of Chantix have little or no energy, The ache in my legs and neck are horrible and I can not lose weight no matter how little I eat...I have shortness of breath and I thought panic attacks, because of how fast my heart will beat and I can not muster yup energy...I use to only need 5-6 hours sleep...now I sleep 10-12 hours a day...I quit my job, thinking I needed to concentrate on myself and I force myself to have more energy as to lose the 45lb weight gain...But I still have no desire to smoke.....