Burning sensation at the end of urination, frequent urination and stool discharging with small amounts of urine and stool discharge, there is residual urine and stool, severe pain in both the anus and the opening of the vagina with a feeling of needle pricking, even walking became a bit difficult as it makes it more painful, the pain is not consistent. What do you think I have and what is the best antibiotic that can be used in this case since I think I have some sort of real bad infection?