I would give the Wellbutrin a month.
Watch for increased heart rate...that is the most common reason people discontinue.
That actual antidepressant actions will be slow to appear though like with other antidepessants.
People with low dopamine levels will feel energized and more confident as first changes. People with high dopamine already, may get the palpitations.( I saw many people complain of this heart rate effect over the years).
Some people believe Wellbutrin has mixed actions. These drugs can get pretty complicated to understand.
The anti-inflammatory actions mentioned in this article are fairly new.
If your PN has an inflammatory component...you may see improvement.