these are of withdrawal symptoms and probably from Cymbalta.the fastest way to feel better it is to go back on it and then decrease the does over a three-week period before you stop again.
My vote is on withdrawal. The Wellbutrin is probably not the major problem, but the cymbalta has a reputation for horrible withdrawal symptoms.
Since you know the term cold turkey, I assume you knew about withdrawal. Welcome to it. Either go back on both meds and work out a slow taper with your psychiatrist, or suffer and hope this passes.