Check for iron! This was my problem, I had none. I'm feeling much better since going on a course of iron supplements.
Also, if you want to test further, ask for a MTHFR gene test as about half the population have a particular gene that interferes with certain vitamin and mineral absorption. I have it and am on an activated vitamin B tablet to help as the normal ones don't do much for me.
Till 5 month i also had same problem.listen to ur body .take rest.pay attention to ur diet as well...include milk,.curd,juices n coconut water in ur meal...