Phobia of Dirty White Socks

I have a phobia of dirty white socks. I cannot touch them at all. If I see any I lose my appetite and it feels like my skin is crawling. If I see one in the floor or anywhere I go the other way. It also bothers me when I can see the bottom of a sock that is dirty on someones feet. I have tried to tell myself that its just a sock but that doesn't. I have also seeked professional help but they don't know what to do.