Muggle,
The trouble with the symptoms of anaemia is that they can be the symptoms of many other things too.
Are you very stressed at the moment? Because those symptoms can be put down to anxiety too.
I's probably nothing to worry and about but if it's interfering with your school work I'd go and talk to your doctor about it. It could be something very simple, like a virus perhaps. I got very similar symptoms to that when I had glandular fever.
Hope you feel better soon