Hi Marie, I felt the same in the early stages, and so far this pregnancy has been so different to when I had the girls (from what I can remember!) Despite being the easiest pregnancy I've had, it's still been uncomfortable and frustrating!!
Your hormones will be all over the place at the moment, and the tiredness does feel like it is all consuming. The only thing I can recommend, is rest as much as you can, I should take my own advice really, but I know it's not easy to just drop everything. Try to avoid coffee, as having it will make it difficult to sleep, and have plenty of warm baths as this will help relax you, and also relax your muscles. Feel free to email or text anytime you fancy a chat or a moan, you have my number.
Take care, and REST!!!!
Claire xxx