Help! Need advice!!

So last wednesday I was diagnosed with a yeast infection. I went to the doc, they have me diflucan. On Friday, all my symptoms were gone. I attempted to have sex on Friday and it just burned so bad! It's still reddish down there too. I looked it up and saw that a yeast infection burns your skin so that's why it could burn? Has this ever happened to anyone?! Or any advice?! Please!