Energy Tips

I'm only 9w2d but I'm seriously lacking in energy. Does anyone have any tips to add some fuel into me? I have a 3 yr old to look after, cleaning & cooking but I just can't find the strength to do anything and mornings seem to be the worst. My boy starts school next week and I'm scared I won't be on top of it all. I eat fruit & yoghurt for breakfast but I've gone off coffee. I know light exercise can help but I can't find the time in the mornings as hubby leaves early and I need to get my boy up.