Hi,
Noted your history of having anal sex then vaginal after cleaning penis with your boyfriend, UTI like symptoms particularly at night, taking cranberry juice, 
vitamin C and lots of water.
The sexual activity as you have mentioned can surely cause 
Vaginitis, 
Pelvic inflammatory disease and UTI.
Hence I would advise you the following in such a situation:
First of all, send the sample of urine for routine, microscopy, culture and sensitivity before antibiotic is started to get proper diagnosis and results as a single dose of any antibiotic can give false results.
Send the blood for lab for CBC, 
kidney functions.
Ultrasonography of abdomen and pelvis particularly for genitourinary symptoms.
Consult your Doctor for clinical evaluation and correlation with reports.
This will give proper diagnosis and a plan for management.
Complete the course of an antibiotic for long,
If there is any associated problem, it will also be treated.
Continue taking plenty of oral fluids.
Do not engage into dangerous sexual activities.
Hope I have answered your query. Let me know if I can assist you further.
Regards,
Dr. T. Chandrakant, General Surgeon