Hi and welcome to HCM
Itching and white colored discharge are commonly seen in fungal infection
However, since you have used an anti-fungal preparation without much relief, it is adviced to get a culture of the white colored discharge.
Culture and further senstivity will determine the organism and the medication to which the organism will respond.
Whether the infection is a STD
can only be acertained after culture of the discharge.
Till then it is advicable to abstain from sex.
In case your partner also suffers from same problem, get it treated too as recurrence can occur.
Thanks and take care
Dr Shailja P Wahal