What is this and whys it hurt??????

Okay i had a yeast infection from some antibiotics and then a day after the yeast infection symptons showed up i got a sore down there, it was red and sore at first and then it started to itch.. and now it just hurts and i just found another one. Im trying to get rid of the yeast infection and i dont know what they are or what to do about them i have two of them and my docters appointment is in a week. but i just wanted to know if any one on here knew what they were.... so if any one has anything let me know thanks for you time later ya'll