I was right where you are just a few days ago, and I didn't have energy to do much of anything. Like you, one small task and I needed to lie down. I suggest listening to your body. Don't push too hard activity wise. Rest. Drink plenty of water. Eat some healthy food if you can ( fruits are good). It gets better. I'm just at day 9 and feel so much better.
Way to stick with it. The group really is supportive, so post, ask questions, whatever you need.