Hi Chris,
First off, sorry...but I am going to say something that may shock you...it is not your fault!
You may just be suffering from dehydration. If you do not understand it or know what the signs are you may just be ignoring it.
Dehydration is insidious. It causes exhaustion, depression, pain in the legs and all of the joints, short-temperedness, sleepiness...the list goes on.
But dehydration is not just water but a mix of sodium (salt), potassium and other trace minerals.
The first thing that you could do is start by keeping a water bottle mixed with some honey and lemon juice in it (I add mint)...it is very refreshing and when you like what you drink you drink more.
You need more salt in your diet so that it keeps your body hydrated (but not too much).
You may also be anemic or be suffering from B12 deficiencies or other vitamins so get your blood work done and have a doctor look at it.
A nutritionist could help you too. You may need more protein in your diet (it helps to build muscle and can help with your iron levels too) as well as more fruits and veggies.
Talk to a specialist. Soon. It is also important to make sure that there are no other underlying problems as well.
But do not worry too much about the exhaustion...yet.
First, try increasing your fluid levels and eating a bit more red meat. Avoid sodas and sugary drinks. Alcohol can also dehydrate you so increase your fluids if you drink alcohol (orange juice?).
Exhaustion breeds exhaustion...meaning the less you do the less you feel like doing...So get up and go for a slow walk with the kids, bring water and salty snacks...the more you walk the more energy you will have and the better you will sleep.
Let us know how you are doing.
Sharon