It seems like you're having a yeast infection. Yeast infection is caused by a fungus called "Candida albicans" which is normally found in small amounts in the vigina. This infection is often found on people with weakened immune system, in most cases it is not the sex activities which bring women yeast infections.
Women with yeast infection may develop any one or all these symptoms including:
Pain/itch/burning at vulva area
Pain/itch/burning in vagina
Pain during intercourse and/or urination
Cottage cheese like vaginal discharge
Swelling and pain around the vulva
You should see a doctor and get prescriptions to avoid a worse condition. Also try to eat lots of yogurt may help you a lot. There's a herbal medicine named SPAM also works well, you can google it and have a look. Hope you can get rid of your ailment soon. Good luck!