So you have a massive loss, pat on back and well deserved coz it isn't easy. Why not start with a week of WS and then see if you can switch over to 100% if you want to see faster results, better than not getting on the wagon at all maybe??
I do feel awful for about the first week, I think mostly everyone does, light headed, strange, tired, I try not to plan a busy week, or any exercise until I'm feeling energised by the ketosis, I know that can be hard if you're at work and stuff though.
Chin up mrs, you know you can do it !!