I am on day 19 and all I ever feel on any vlcd is immense lethargy and tiredness. If the kids mention going for a walk, I literally can't do it. Its just a side effect for some people in ketosis, id say. Despite drinking copious amounts of fluid, I only feel tiredness.
I remember on week 9 of lipotrim, I had to abandon the diet as my body was telling me that was enough. I felt like my body was an empty shell and didn't have the energy to even laugh. At that stage, all I could do was start eating again and boy,did I eat!!!! I packed on all the weight again and more so this time I aim to listen to my body and stop when it tell me.
The tiredness may go, but for me, I just deal with it as best I can and sleep as much as I can. Thats all you can do but make sure that you listen to your body also. best of luck hun.