What Causes Dark Red Discoloration On Breast?

Hello am 50 years old lve had my breast scan in januray this year . It was . But last I went to the bath room and look in the mirror one the breast is dark red.and touched it and it feels very dry horrible .and the other is normal and soft . It worries me to death .allday.And igoing a big change .my gott sty.and stop my period and started again .

Sorry am going on. What's wrong