This problem isn't about Tea Tree Oil. ANY substance with antifungal properties could end with an extracellular fungal infection. The problem is there is a hormonal or cell-mediated immunity problem that allowed the yeast penetrates the cells. How can you think that Tea Tree Oil or any other topical treatment can be stronger than all the systemic drugs you are taking. You have to look at what is causing the infection. Your CD-4 count is very important because if it is low (< 500 ) there isn't way to end with it. Also, you need a complete hormonal panel because an endocrine problem cause persistent candida infections. It is time to stop trying more and more things without knowing what is causing the persistent infection. I hope this help you.