Why does it hurt when i urinate, and sex is so painful and my vagina is so sore but the doctors cannot find a cause?

Rest: Take a break from sexual activity to give any irritation a chance to heal. When you do resume having relations be sure to use adequate lubrication like petroleum jelly, etc. Assuming urine analysis was clear, the urine problem could be a result of vaginal irritation or diet, so experiment with that. If it is irritation from sex, do it slower & be aware of even mild discomfort. Increase fluids.