This sounds as though it could be a fungal infection. Fungal infections burn and itch and can even crack and bleed and be very painful. If you can be seen by a physician, they can take a sample and look under the microscope for the fungus. If not, an antifungal powder might be better suited to begin with initially and then once the area is less irritated, you could use one of the anitfungal creams. Also, note that if you have other conditions such as Diabetes or other health issues, these can be difficult to clear up once they have gotten as bad as yours seems to be.