Have something that you will particularly look forward to every evening at 8.30, that is just for you. A particular tv programme, a phone call to a friend, a bath, whatever you like.
Look forward to one hour a day that does not involve children, housework or anything else you just have to do.
If your daughter has a nap, take the opportunity to put your feet up or chill out on the internet. Don't fall asleep!
Watch your carbs. You need a certain amount every day, but don't fall in to the trap of gorging on them. It will make you very sleepy.
Get blood tests and check there is no amenia or other underlying problems.
Look after yourself,.