What Causes Burning And Swelling In Vagina After Intercourse While On Contraceptive?

I have recently changed my contraceptive pill and have been experiencing severe thrush. Usually when i have it, it goes within 3 days, but i have used a pessary and cream and still it seems apparant. When it feels like it has eased off i have intercourse and experience a painful burning after and when i pass urine shortly after. It looks very swollen also and is very uncomfortable.