I can't pretend to understand what this means entirely myself, but my neighbour is an accupuncturist who treated me a bit and he said feeling tired and "cold" and drained all day and then hot in the evening is a sign of a serious yin deficiency - basically a serious energy imbalance which is best helped by taking herbal blood and energy building teas or pills, as well as some accupuncture. He said to eat warmer soups and foods, and practice yoga or some gentle strengthening. These are helping me.
He said yin deficiency is very common in mothers as we are up & at 'em so quickly after our babies are born and don't give ourselves (aren't given) time to re-build our blood and energies. also often forget to look after ourselves in general. I know chinese medicine uses a whole other language for understanding our bodies, but it is the only paradigm that has actually helped me get healthier in the past - I recommend seeing if it helps you.
best wishes and lots of rest to you!