What Causes Vaginal And Thigh Area Itching, Redness, Lines With Sweating, Discoloration?

Hi, area between by thighs and vagina are red and itchy. It's been going on for about a week now. It does not itch unless the area is touched. At first it was just a little line on both sides by now the lines have gotten longer and it's starting to itch more often. I have been keeping the area dry; however, after I use the bathroom I notice that its almost like sweat on the area. It also has a light yellowish color left on the rag after I clean it. Do you know what is wrong with me?