What Causes Burning Irritation And Yellow Discharge From Vagina?

I feel like there is like a cut on the inside of my vagina i went to the doc and they thought i had a uti and said it was irritated they gave me antibiotics but ive been on them for awhile now from a previous problem. I have a slighly yellow discharge and alot of it. It burns and is uncomfortable what could this be? its been happening for a week now and is not getting better