18 weeks 3 days pregnant and battling with thrush!!!

Hello ladies. I am currently 18 weeks pregnant and been struggling with thrush for a week and more now. I been to the doctors and been told i cannot take any cream or pessaries either which left me with an only option:yoghurt!!!! Its just not seem to help either. I read somewhere inserting a clove of garlic would help to clear yeast infection. I just want to ask what you all think about it also could using a garlic harm my baby??? Im willing to try if its gonna help? Is so painful and uncomfortable. I also worry that thrush might harm the baby. Im going paranoid:((( Thank you.