Hi, and thanks for your medical question on eHealth forum!
The white vagina can be due to low estrogen or due to persisting fungal infection. Yeast infection or thrush is at times very difficult to treat. You may need to take oral antifungal pills twice a week for 3-4 weeks along with local application of antifungal cream. There are many types of antifungals available. Take an OTC antifungal with a combination of two or more anti fungals. Use both oral and local application.
Get serum FSH, LH, estrogen and progesterone tested. You may need some hormone supplements or hormone replacement therapy. Take care!