What Causes Vaginal Itching And Discharge And Stomach Pain?

i am 22yrs old and as been suffering from abnormal discharge since some yrs back.actually i never know is not good not until wen i started feeling pains in my stomach,i had pain when i wanted to urinate and as well itching in my virginal. i teated my self with mycoten tablet with inserter,mycoten cream,and flagy.i still have a yellowish discharge what should i do