What Causes Vaginal Itching And Discharge, Stomach Pain, Headache And Muscle Ache?

Dear doctor, Thank you for your time reading this. I got unproteccted sex and after 3 days i got the following issues: Discharge of my vagina ( a lot secretion, white) Pain under my stomach; Headaches; Muscles pain; 1. Doctor Told me that i probably have Clamidia or Gonorrea so after 1 one week and 2 days He decided to do the STD test . Results = negative. 2. Doctor gave me metroniazol 500 Gr. 4 pills x 1 time. After 3 weeks i started to have itching in my vagina, hands, feet , legs and arms ( all body) and stomachache, under backpain. Well the doctor decided to do anotherSTD test because it was too early. Result= negative. Today i still have symptoms like itching, headache, backpain, and muscles or articulations pain specially in my arms. I didnt do yet the other test because i need to wait 3 months. Would you please tell me what can i do and what do you think i m facing right now. I feel completely anxious about this. Many thanks for your kind answer