Help what is this, I’m scared!!!

a week ago me and my boyfriend of 1 year had sex and a few days after i got this spot on the outside of my vag lip on one like directly on it but that one is hard to see. now i believe there is one at my vag opening because when i pee if it goes to the back it stings and if its on the lip it stings. ive never had this before and im scared it hurts but its not like a bump or anything just flat on the skin and it hurts to touch and its like my whole vag hurts not bad but just enough pain to know its there. now i was having discharge that was white but when i wiped it was yellow and on my pad like a light yellow, and a couple of days after i got my period but the little things are still the and hurts. its not itching or anything its just there and painful