Hi, Barbie. Congratulations! Three months is awesome!
At two and three months, your brain chemistry is undergoing some changes because of quitting. It is normal "not" to feel satisfaction or pleasure at three months. Your mind may be having some internal discussions about whether this is all worth it, and what we call "junkie talk" and negative thinking are very common. If this is what's been happening (re the weight gain, for instance), then please hang in there. The mental battle will stabilize within the next few weeks. You're still in withdrawal for the better part of a year, though the tough work takes place in the first 16 weeks.
Your metabolism has slowed down and you require about 200-300 less calories per day to maintain your weight. However, it's not recommended to go below 1200 cals per day. Rather, one should increase fat-burning activity. As far as I know, wellbutrin does not make you gain weight. If when walking, you take occasional spurts of quick walking for 19 seconds, this will increase your fat-burning.
Smoking and anxiety are often related. When you quit, your emotions come to the surface in a raw way. You can no longer deal with them by lighting up for comfort or consolation or to cope with whatever is happening at a given moment. As you are learning to deal with those emotions without nicotine, your anxiety may rise. So, if your anxiety is general, in that it's related to everything, and not to one specific fear, at this stage of quitting, it's not unusual.
Having said that though, if you are concerned enough to bring it to the board, I would strongly urge you to see your doctor about this, just to have an assessment done and have him or her address the weight gain issue with you too. Maybe you need extra help to get over the hump of the next few weeks.
If you're not a member of the Stop Smoking Center (see our Outside Resources) then I urge you to visit there.