What Causes Brown Colour Moistness Around The Anus Spreading To Labia And Is Very Itchy?

I am a 27 year old woman and am Caucasian. I have always had a brown coloring around anuses but now it's multi colored brown purplish and white and has spread into a much bigger circumference and has also reached into my inner labia. I also have a skin tag attached to my anal opening the size of a sunflower seeds and it is often sore and itchy. I am itchy from front to back whenever moist, after pool or shower but especially after sex. The scar from the tear during childbirth all feel inflamed and elevated at same times. Bowel movements hurt and are either constipation or loose and I get a pressure pain when I'm about to go along with blood from tearing. Please tell me if this is all related or if it's something simple that I have put all factors together when it's nothing!