I used to have weird spaced out feelings after my chemo. They told me it was to do with the steroids which they gave me along with the anti sickness medication. My chemo always left me drained. I'd have mine on a Thursday and after I got home from Radiotherapy on Fridays I would go to bed and stay there till Monday morning. It did seem to help so I'd say take every opportunity you can to rest.
Best wishes for the rest of your treatment and keep posting to let us all know how you are getting on. xx
