my vagina is in shambles

i just want a normal vagina ya know? for the past 3 months my vagina has been in shambles. constant itching. tons of dry white discharge mixed with clear watery discharge. its so much discharge pantyliners cant even help. and it always gets worse after i have sex. terrible itching a swelling and discharge. i tried rephresh pills? nothing. i tried coming off of birth control? so far nothing. what the hell is going on. pls help. 
i have been to the doctors and have been tested for literally all sti's std's and viginitis infections. i got the works and everything came back negative. this is seemingly happening for no apparent reason. i haven't had a yest infection in years, never had trich, bv or anything. never had an sti.