What Causes Burning Sensation And Itching In Vagina After Applying Toothpaste?

i applied toothpaste onto my vagina cause it was previously itching and i was in pain and a friend told me that applying toothpaste will ooze the pain away. As soon as I did, my vagina burned really bad and I washed it all off and what not but my vagina has been even more itchy and its difficult to fall asleep. I have never had sex so i dont know whats going on