Hi, it usually takes a month or so to completely "absorb" into your system. If it is giving you a lot of symptoms, let your doctor know -he or she may adjust your prescription. You should not have a seizure if you stop - your doctor would not have prescribed it in the first place if that were a possibility! If you are taking other things prescribed by other doctors, you hopefully let the Wellbutrin-prescribing doctor know before he issued you this prescription; otherwise you may be experiencing something relating to combining medicines, so make sure you contact your doctor and let him/her know. If you feel strongly that you do not want to take this, let your doctor know as well and he/she can tell you the best way to "taper off." Be sure to let the doctor know about the headaches. Is there something other than the Wellbutrin that could be making you feel like crap?
The seizure problems are with benzodiazapenes when stopped abruptly, not with antidepressants. The main reason is that benzos target GABA, which is involved in seizures and anti-seizure meds. Other neurotransmitters are targeted by antidepressants. As for the wellbutrin, know that with any antidepressant, it takes most people 4-6 weeks for them to start working but the side effects start right away. Quitting this med should be easy because you haven't been on it long, it isn't one of the really bad ones for quitting, and your brain hasn't had time to get used to working with it yet so it still remembers how to work naturally and hasn't shut down neurotransmitter receptor sites yet the drug makes the brain think are no longer necessary. If anxiety is a big problem, this drug is one of the most stimulating antidepressants and might make it worse, unless depression is the cause of your anxiety, which is common. Your psychiatrist should be able to taper you off this pretty easily.