Hello. Thank you for coming to JustAnswer with your question, and welcome.
If you did have a yeast infection, the residual itching is likely caused by the yeast that has infected the surrounding tissues outside of the vagina. You can use miconazole or clotrimazole cream for this. Hydrocortisone and Lanacane will not treat the cause of the itching.
Warm sitz baths also help with the itching and allowing the area to heal.
If it does not improve significantly within the next day, since you have used the one dose treatment, you should see your doctor for an exam to rule out any other causes of the itching and discharge.
Here is a good link for more information: Vaginal Yeast infections
Hello. I see you have added some additional information to your post while I was answering your question.
There are a number of home remedies that are supposedly helpful for frequent bouts of yeast infections. But they have not been studied to confirm that they are either safe or effective.
There have been a few small studies done using Lactobacillus (both orally and intravaginally) to reduce the number of yeast organisms in the vagina that are responsible for causing the infection. This type of treatment still needs more research done to confirm its true effectiveness, however.
The link I gave you in the above answer has some ideas for things you can try to reduce the number of infections you get. You may also want to see your doctor, or GYN for a discussion about your problem, to try to determine the underlying cause of your repeated infections.