You definitely need some rest. When I get really bad I do notice slower movements and I do get the cognitive issues. I'm finally learning at what point to stop. If I wake up and my back feels weak then I slow down and do nothing at all.

I know it's somewhat normal to walk into a room and forget why you even entered the room, but when I start doing something and I'm constantly stopping in mid process to figure out the next thing to do, then I know there's something wrong. I strain my brain sometimes trying to think of the next step and if I wait a minute or two the next step will come to me. I notice this most when cooking a meal. I think it's mostly sequential things that I have a problem with and it's not every day, but it does happen on those days when my movement is slow. I was beginning to think I have Alzheimers or Dementia, but my daughter who is an RN and works in a nursing home said that this isn't like any of those. It seems like my thinking isn't as sharp as it used to be either. I'm trying to write a science fiction novel and I keep forgetting names and details. I have to make up calenders and write in events to keep things straight and I have to keep referring to a list of character so I don't use the wrong names. At least I've got an outline now to keep me on track. I hope your cognitive problems aren't this bad. I wouldn't wish this on anyone.