Back pain and discharge. Vaginal walls.

I am having lower back pain and vaginal discharge along with irritation and itching on the outer walls of vagina. I had my periods on 24th of July which was on the right time thereafter I started having problem in urinating from 3rd day of period that is while releasing the urine which increased every day I had difficulty and pain in lower abdomen and I had my periods again on 5th of august which lasted for 3 days and then again the back pain started however no pain while urinating now, I again had my periods on 25th of August which are on the right time according to 24th July. however, even after the periods are over I am having back cramps and vaginal discharge followed by itching and irritation on vaginal walls.