How To Cure Sore Vagina?

Okay, so I had sex for the first time last Saturday, and for the second time last Monday. And now, for about the past 3 days, my vagina has been really sore to the touch, itchy, red, and this morning there was a white discharge and some bleeding. I'm not sure what to do about this, is it just a yeast infection ? or could it be something worse ?