Budeprion and neck and shoulder pain

I have only been taking Budeprion for 4 days now, and the last 3 days have been excruciating! Horrible neck and shoulder pain that comes and goes. I wake up fine in the morning, but right around lunch time or a little after my upper back, shoulders and neck start to tighten and I get a terrible headache - usually only on one side of my head. I also have a fuzzy feeling in my head, and have a hard time focusing.
The pain lasts until I go to bed, but then I wake up feeling relatively ok again in the morning.
This is the first antidepressant that I have taken, and I know these kinds of drugs can take a couple of weeks before you start to notice anything, but I am really scared to keep taking the Budeprion because it makes me feel so awful. The worst part about the situation is that doctor actually prescribed me Wellbutrin, not this generic, and I just found out today that my insurance company covers both. I REALLY wish I would have done more research on this drug before I got the prescription filled. Now I have to wait a month before I can get it switched.

A couple of days after switching from Wellbutrin XL (which was effective for me, with no side effects) to Budeprion XL, I began to experience feelings of panic, a choking-like tightness in my throat/neck area, and extreme tension throughout my shoulders and neck. (I have never had a panic attack before.) My doctor said that my symptoms sounded like anxiety. Neither of us made the connection to the recent switch from Wellbutrin to Budeprion. These Budeprion XL side effects began each day in the late afternoon and continued for at least two hours, sometimes longer. Nothing relieved them. I tried relaxation breathing, yoga, meditation, and even Ativan! After several days of this torture, in desperation for some relief from the panic/tightness/tension, I drank a glass of wine when the symptoms set in. The symptoms grew even more severe. It finally occurred to me that the Budeprion might be the source of this frightening problem, and I insisted on being switched back to the Wellbutrin. Ta-da. No more freaking afternoon attacks. A few months later, while experiencing some lower back pain, I took a Budeprion by accident (I found a single tablet in my desk drawer and I mistook it for a codeine-based pain tablet that has a similar appearance...I know--a dumb thing to do!) Hours later, the original side effects returned: extreme panic with neck/shoulder tightness and tension. I have not taken Budeprion since that day (about three months ago), and I have never again experienced those side effects (or any similar symptoms). The name brand Wellbutrin XL is working effectively for me, with no side effects. Because of these experiences, I am convinced that Budeprion XL's contents (or composition) are very different from those of Wellbutrin XL. They may or may not have the same chemical formula, but they certainly do not react the same way in my body.