What Causes Vaginal Itching With Discharge And Burning?

hello dr . I am so worried what i can have , for the past 3 wks i have been having vaginal itching but on the outside. when the discharge is clearish and whitish come out and am wet it make me itch bad.. these past 3 weeks ive bought 4 different creams for the itch and it hasnt helped or either gone away ,, i have red and burns.. the weird is that i dont feel itching in the inside can you please let me know what to do you think if i am diabetic its got something to do with it