What Causes Thick Discharge Form Vagina?

hi, i have been experiencing thick discharge from vagina, itching around the vulva but no rash or broken skin, a strong odour when urinating, and a very sensitive and painful to touch cliterous. I have had swabs taken but they came back negative and i definatly dont have thrush which is what the gynocologist thought i had. I have been experiencing these symptoms for over a year now and have seen doctors and gynocologist who dont seem to know what it is. Any ideas on what this could be?