You might be suffering from urinary tract infection
as evidenced by increased frequency of urination,pain during urination, nausea
etc. I would advise you to get certain investigations done, like Urine routine and microscopy, urine culture and sensitivity ,complete blood picture. Based on the reports , you might need some antibiotics.
In the meantime, I would advise you to drink plenty of water at least 8 - 10 glasses a day to flush out toxins, if any ,from the bladder . A glass of cranberry juice might also help.
Ensure you maintain good perineal hygiene.
Empty your bladder at regular intervals .
If sexually active, empty your bladder before and after intercourse.
Hope this helps.
Dr. Divya Kuttikrishnan