I was having the same problem a few weeks ago, most mornings I had to sit on the toilet to blow dry my hair because I didn't have the energy to stand up. I saw my gp who thought I was anaemic. Blood tests showed my iron was low but not overly so however my vitamin D levels were extremely low. Since then I've been taking 2 vitamin D tablets & an iron tablet in the morning along with my pregnancy multi vitamin & I do feel better. I still fatigue easily if I over do it but as long as I pace myself & rest I can get through the day without falling asleep.