Vaginal infection. For every time?

Have dryness, itching ,pain ,burning  in vagina l  rt side opening everytime after  sex.  At least  3months once I get the same problem .when it  came  at 2018 for the first time I suffered a lot .doctor checked the area and gave me doxy1,gudcef 200, bromezer,vozet,intiwash then symptoms subsided.  I take the same medicine for the past 2 yes when ever symptoms develop.if my husband use condom I  will never develop such symptoms  I m 40 yrs,taking bath 2times a day and I have white discharge problem  but nt get cured  by medicine .I took pap smear, HPV test before one year (negative) and pID problem.but I don't have any extra marital relationship. I want to know the reason doctor kindly guide me.shall I use the same medicine for every time??