Suggest Treatment For Discolored Skin Due To Tinea Versicolor

i have had a problem with my skin for the past 5 years. it started to discolor on my back and it has slowly spread around to my stomach. Now it is spreading to my neck and legs. I have been to 4 doctors and each one told me i had tinea versicolor but none of the meds they gave me worked. My skin also itches and I have sores all over my back.