Hi Joanna. My toes and fingers sometimes turn purple white when they are cold, which is often but I've never had it extend to my legs. My only thought would be (since it sounds like circulation) have you tried keeping your knees slightly bent when standing? I think this is something they have soldiers do because standing straight can effect your circulation. I understand your depression. I was there last week. This disease is so unpredictable and most of us don't get to the bottom of what has caused it. Just when I think I've made progress something happens the next day to erase it. I am sorry you are sad and hope you'll feel better soon.