Yeast Infection?? PLEASE HELP

for a few days I've had some slight irritation on my vagina. It was nothing major just a little bit of itching. I had some pretty rough sex with my boyfriend two days ago and the next day my vagina was swollen. This is usually normal for me after rough sex but when I looked at it EVERYTHING was swollen. My labia minora and the whole area around my hole. It was so bad that I couldn't close my legs or sit properly. I was scratching a lot so I don't know if that's what has caused the swelling. I applied some calamine lotion and the swelling has gone down a bit but it still itches really bad. I know it can't be an std because it was itchy before I had sex with my boyfriend. But it got worse after I had sex with him. Can someone please help and tell me how to make the itching stop???