Am I using too much soap?

I bathe for 30 mins everyday..and I use Dove soap. Each bar of soap lasts for only 3 days. So I use 2 bars in a week. When people hear this they tell me that I'm using way too much soap. I also use bathing gloves in my bath and I lather a lot. My friends tell me that if I use too much soap, my skin will blacken and become dead. Is this true?