Step 1 - see your GP, get them to do a blood test, this will check for things like anemia, thyroid issues, or anything else lurking.

Step 2 - see a naturopath. What you are describing is exactly the same thing I had - the exhausted insomnia is the giveaway. My naturopath diagnosed 'adrenal exhaustion' and put me on some foul tasting herbs (plus a few mineral/vitamin supplements) and I noticed my sleep and energy levels improving after about 10 days.

Step 3 - book the little darlings into child care or family day care for a day a week and have yourself some 'me' time. It is well worth the investment