red, itchy, and sometimes turn into sores

The fore skin of my penis became red, itchy, and sometimes turn into sores which have puss. Once the sores are there, it will be there for weeks. And it disappear by itself. But I realized that it happened only after my masturbation especially after frequent ones. It has been this way on and off through out the years. Was it a kind of disease? How should I avoid it.