Suggest Treatment For Painful Urination And Cuts On Vaginal Opening

my baby is 6 months old, i had sex for the first time yesterday morning with my partner. The next day (today) in the afternoon I started to feel really sore down below and now I am in agony when I try and urinate, it really stings that I have to stop and start when I pee. It looks like a cut at the entrance to my vagina and it smells, do I need to see my doctor? Please help