If you’re in a subacute crisis I’d see your family doc to start while waiting to see a psychiatrist. We see A LOT of anxiety/depression. I usually punt with bipolar/schizophrenia and personality disorders ;-). I haven’t ever seen a psychiatrist treat depression/anxiety any different than I would.
Obviously I don’t know your history but sending someone out on Wellbutrin with prn Xanax seems like a weird combo. I agree with you that typically a medicine that increases serotonin would be used if there is an aspect of anxiety which you described and the Xanax suggests they saw as well.