I'm 25 Years Girl. I'm Facing Problem In Periods Time.

I'm 25 years girl. I'm facing problem in Periods time. Normally periods taken 3 days time. but this time it takes 6 days and still going on. This time i feel lot of stress, anxiety, Pain , Lot of building and still going on.
so pls tell me why this all happened and pls give me a way to escape.