I'm 24 years old and work from home. I have a huge problem with my energy levels. I try to eat well, exercise when I can (I walk everywhere - sometimes miles and miles at a time), I drink plenty of water (it's like all I drink), and a few weeks ago I changed my sleeping routine to get up at 7am (I used to get up at 9am and my days were highly unproductive - getting up at 7am allows me to be much more productive). I am also taking steps to improve my mental health by thinking positve all the time (I used to be a very negative person), and I am learning how to meditate.
I feel like I am running on autopilot. I have no problems with motivation to do things - like starting work. In fact I enjoy my work a lot. If I need to go out, or make dinner, or clean the flat, I have no problem just getting on and doing it. But all the time I have no energy. It's not like I'm tired, I just feel like I am a machine - just doing things. I feel empty. My brain and eyes feel very heavy. I have this feeling constantly, all day every day. It's a steady feeling - it never changes. I have no peaks or dips in my energy. It's just always like this.
At first I thought maybe I'm just fed up with life the way it is. But I've been taking steps to improve myself and my life, and I'm happy, just not got any energy. I also thought that maybe it's due to the lack of sunshine. I live in Milan, Italy. This time of year is supposed to be very sunny and warm, but we've had nothing but clouds and rain for almost 2 months now.

I also thought that maybe I am sleeping too much? I get about 7-8 hours a night. People say that's standard, but maybe it's too much for me?
Does anyone else have this problem? Or has anyone had this problem and overcome it? I'd love to know what you did.
Any tips will be appreciated!
Tina