I can’t function properly right now.

I walked miles up to 26,000 ish steps. I mentally can’t function right now though. I have barely got anything done for the past few days. I don’t even want to get up to go the toilet right now. I keep getting dizzy since I started the iron tablets again. I can’t think straight. I’m fine when physically doing stuff but when it comes to actually doing stuff that needs doing I can’t mentally deal with tasks. I keep feeling emotionally drained. It’s annoying me. I need to do things. I just have lost my ability to concentrate on things. I feel far away mentally and so tired.