Suggest Treatment For Vaginal Discharge With Itching

age: 25, height: 5'1", i am having a vaginal discharge (light yellow in color) with itching. this usually happens after i drink coffee or sodas. i had this problem for a year now. at first it didn't bother me because it doesn't happen all the time, i never consulted a doctor.but now it's really bothering me. what's the best thing i can do?