BV CONSTANLY COMMING BACK!!

WHEN I WAS PREGNATE THEY TOLD ME I HAD BV. I HAD EXTREME ITCHING AFTER SEX AND A SMELLY DISCARGE.. THEY GAVE ME FLAGYL AND AFTER I HAD THE BABY MAYBE A YEAR LATER I GOT THE SAME SYMTOMS AND THEY GAVE ME THE SAME THING SO.. NO ITS 2 YEARS AFTER FIRST HAVING IT AND I FEEL LIKE IM GETTING IT AGAIN!!! ITCHING NOW AROUND THE VAGINAL OPENING BUT THIS TIME NO SMELLY DISCHARGE.. I NOE ITS NOT CLYMADIA OR GNORREHA.. CUS THE LAST TIME THEY TESTED ME FOR THAT. AND WHEN I FIRST GOT IT THEY GAVE ME A STD TEST SINCE I WAS PREGANTE... I ALSO GET LIKE SHARP SHOOTING PAINS IN MY VAGINA.. WHAT CAN I DO IS THERE ANY STRONGER MEDICATION THAT CAN TAKE THIS AWAY FOR GOOD..?? AND COULD IT BE THAT SOMEHOW MY BOYFRIEND COULD BE RE-INFECTED ME.. OR HIS SPERM IS TOO STRONG?? IM ALSO ON NUVARING SO SOMETIMES I TAKE IT OUT AND IT KINDA FEELS BETTER BUT I DONT NOE IF ITS JUST CUS I NOE ITS OUT.. DOES ANYBODY ELSE HAVE THIS PROBLEM... ITS REALLY IRRIATING MY MOM SAID IVE ALWAYS HAD PROBLEMS WITH MY VA JAY JAY.. BUT I DIDNT THINK IT WAS GOIN TO BE SUCH A REAL PROBLEM! IM TO THE POINT WHERE IM LYING TO MY BOYFRIEND SAYING THAT IM ON MY PERIOD JUST SO WE WONT HAVE SEX ITS HORRIBLE!!