The medication you are prescibed are mainly for the condition of neuropathic pain
. The symptoms which you describes as pain should ideally improved from these medication and normally it take time to improve the condition.
Regarding the other symptom of numbness
and giddiness, these medication are not going to help much. It is the normal process of healing of the nerves after which only these problem will subsides.
It is also important to make the diagonosis that these symptoms are becasue of neuropathic pain only and not because of some nerve compression some where in the neck.
Thanks and take care