Yes it does get better and yes it’s normal to feel so tired at the beginning of your recovery 
So do not worry about it.
Your body has been neglected for a long time as well as it has to work hard right now to find itself a new balance. It was used to live with alcohol in his system and is working hard now to get all the remains out.
Give your body what it needs like healthy food and rest. Sleep as much as needed, hot showers help too. It’s going to be better soon.
You find more information about the stages in recovery in this thread, very helpful:
So welcome here, you are at a good place! This app helped me a lot with sobering up.
Sober for a few years now!
I wish you the same so keep going! 