Try to consult a doctor. It means you might have infection. There will be no pain if you are dry. Sex does not hurt if you are dry. You mentioned pain, this means you have something wrong, like infection. If you feel burning when u have sex and the liquid that comes from your vagina is yellow I mean not white as it should be that means you might have vaginitis and you should see a specialist. This is normal don't worry most women have it. We all go through that. Sometimes it is not from sex ,sometimes we get vaginitis from the underwear, when we don't clean them enough from the soap. Nylon also cause that. I mean the material of the underwear. You might be sensitive to some products.

Try to see a doctor they are the one who will know what you are going through ??????

My heart is with you