Vaginal swelling and itching. Shud i do?

I had vaginal swelling for the first time after my periods two months ago.. I took medicine prescribed by doc . My swelling was gone within three days but I felt sort of dryness throughout the month down there there was no pain no swelling no itching bt it wasn't comfortable even then .I could feel that dryness and sensitivity  there wer rashes on  skin but with time things got better but not totally fine .. i could feel that my vagina was not back to normal like it was before having that infection.. it was still dry .. now I again had periods past ten days . And again m having  swelling rashes on vaginal lips internally .. m not able to understand what has triggered this .. I have bought the same medicene now which my doc prescribed me last time .. I thought it will go with time but occurred again this time after my periods... What shud I do ?