Hi Bunnet,
You sound to me like you might be peri-menopausal -- hope I'm spelling that right. The sleep issue is a big, big clue. A lot of women going into that have a terrible time sleeping. I recommend going to your OBGYN. Might also be that your body's hormone's just need time to get settled after losing so much wt so quickly. The low, low sex drive is also a clue. I recommend talking to your gyno. Get your hormone levels checked and take things from there. Hope it gets better for you soon!
Elia