Extreme tiredness

I'm always tired no matter how much or how little sleep I get and I don't understand. I thought it was normal sleeping at any chance I get but no one else I know seems too. Today I slept from 5 until 10 and I'm still so so tired. My doctor wants to get me tested for anemia but could it be something else? Also due to my regular anxiety attacks and always being anxious my mum seems to think I'm depressed and that why. I'm pretty sure I'm not though 🙄