pain in vagina

hey im 17 and wanted to ask a question about pain concerning my gf. we have been together about 7 months and havnt had sex in about 3. we stopped firstly because she had a urinary tract infection and her docter said not to have sex for a few weeks, but we did. ever since then it hurts her or makes her feel extrememly uncomfortable when anything enters her vagina. it even gives her pain if my pinky finger is inserted, also she doesnt get wet properly anymore, what is the problem and how do i fix this ????