Has a doctor actually looked at it? If not, it's time for that.
Are you straining with bowel movements? It could be hemorrhoids. It could also be a fungal infection, an allergic reaction to toilet paper, soap, wipes, or anything at all that comes into contact with the area, including your underwear (dyes, fabrics, etc.)
We don't need to see a pic of it, but keep the pics for your doctor.