Suggest Treatment For Dry And Swollen Vagina

Hi there. I feel extremely embarrassed but i have had ongoing problems in my downstairs area. Firstly i have had days where my vagina feels swallen and i have discharge that is chunky smelly and yellow coloured. I am also internally itchy. Sex is painful for me as well as any touching internally of this area . I am also sometimes extreemly dry downstairs. When my partner and i have intercourse his penis is sore or goes really red. He says after his penis is really dry. At the moment discharge is milky in colour and of a thin consistency yet the smell is fishy. I have used thrush treatment about a month ago when i had these symptom and it went away for a week but then came back.
Im 20yrs old about 163 cm and weigh 56kg