Suggest Remedy For White Discharge From Vagina And Back Pain

hi.. i am a 18 yr old girl..i have a problem of semen leakage, due to which i think my back pains a lot..the white liquid flows out every now & then.. even if i am not thinking about sex, it flows. i dont know how & why.i am facing lot of problems bcoz of this. i am very very lean. my weight is 52 kg. & my height is 5.6". i used to eat a lot for getting little healthy & fat. but it didnt work. now i eat normally. i dont know what to do. i am unmarried but i had sex many times with my lover. earlier i thought that this liquid was flowing bcoz of sexual desires & if i do sex, i will get rid of this problem. so i did, but no effect. it flows some times more & some times less. some times 2 to 3 days continuously & in a day many times & some times once only.mostly when i have my periods, before that period day, the white will go & then in a day or two, i will get the periods. but now it flows any time... please help me out... please..