my advice would be to dramatically increase your fat intake and see if that helps. fat is the most important nutrient, pure and simple. most vegans dont get nearly enough fat. eat fat with every meal, eat fat in the morning, afternoon and evening. this is very important.
i would also recommend you increase vitamin D to 4,000 - 5,000 IU a day. do you live where you can get sunshine, or is it winter there? if its winter or you dont get much sunshine, then supplementing with vit D is critical. take the D along with some fat since D is fat soluble.