Weary weekend

Just when I think things are going well, my body likes to show that actually it's still in control of this situation.  At least three times last week different people asked me how I was doing and I replied with a really enthusiastic "really well", very well in fact. I felt good at the start of the week but when I woke up on Friday morning I knew that my body was fatigued.  It was a struggle to get up on Friday, but I perked up a bit as the day went on.   Saturday morning was just the same, I was drained.  I had a night out planned on Saturday for a friends 50th birthday celebration and it wasn't looking good for that.  So, soon after 12pm I took myself off to bed and didn't get up until 4pm in the hope of giving myself a little boost.  The sleep was strange, for the first half of it I couldn't tell if I had slept or not.  It was like my dream was about going to sleep and I couldn't tell if I had really slept or just thought about it.  A bit disorientating.  I did feel a little better when I got up and we did make it out for our meal in the evening.
Today things are still not right and it's such a shame because today or tomorrow I am going to fill out my Perrin questionnaire (the same one I completed when i started my treatment so we can do a comparison).  If I'd filled it out on Thursday I think it would have been excellent, but now it is going to be blighted by the past three days.
There's no one activity that I can think of that has led to this little blip, but my general activity levels have been up this month. I know that my average daily step count for May is 6500 and it's normally around 5000, so it could just be an accumulation of this increase in activity.