What Causes Persistent Nausea Post Discectomy?
Nausea not directly from the C6-7 issue.
Detailed Answer:
I read your question carefully and I understand your concern.
One month is a longer than usual time to continue to have pain, most cases patients experience pain relief soon after surgery. Of course each patient is unique and may take longer at times, but if it persists I would consider the possibility that surgery has failed, probably have a control MRI.
As for nausea it is not a feature of cervical disc herniation, at least not at that lower neck level you mention, there is no reason for that. So explanation must be sought elsewhere. One possibility is neck muscle spasms and inflammation of upper cervical levels which may be associated with nausea. In that case since you say to not be taking any other drugs apart from anti-nausea (which?) perhaps a course of over the counter anti-inflammatory medications like Ibuprofene and muscle relaxant like Flexeril.
Other possibility would be nausea being a manifestation of a more general involvement like from an infection, but in that case you should have some other symptoms like fever.
If none of those things is present then it should be sought for some other nausea cause not related to the spine such as stomach or liver issues.
I remain at your disposal for other questions.