You have already received some very good advice from Paxiled...I concur....both are used together frequently and what you have to sort out is the medication effect from the underlying anxiety/depression which may be intensifying, that being the reason the second medication was added...have you tried psychotherapy, which is the best treatment of them all.
These are often combined, though usually for reduced sex drive. But if any medication makes you worse, still another medication is the wrong way to go, in my opinion. Wellbutrin is an antidepressant, whereas Paxil is an ssri and helps with both depression and anxiety, when it works. Each person is individual, so it's hard to generalize, but wellbutrin can cause increased anxiety; it usually is good with depression, but if the combination makes you worse, then that's what you have to act on. Piling up medications to deal with the side effects of other medications has never seemed a good idea to me, but there are depression studies that show combining meds does achieve better results.