Bloody hell grockle, that's so gutting :( it's really horrible when you are betrayed like that.
I've had a similar couple of experiences where I've been 'grassed up' for making a simple tiny mistake - nothing big, nothing that's not easily sorted, and I get called to speak to management for a gentle reminder
one time it was for... forgetting my bus pass. Yes, really. A colleague was giving me lifts at one point but had to go elsewhere in the afternoon. I mean FFS if another public-transport using colleague had forgotten their pass (easily done, right? And has NO impact whatsoever on the actual job?) would they get spoken to like a child, erm, no. 
Anyway. I made it to group today thankfully - the antibiotics have definitely kicked in (I am considering asking for an ENT referral if this becomes a regular occurrence like it was in 2011). Cough is still really irritating so I couldn't take part in the relaxation exercise as I was spluttering everywhere 
It was a good session where we were talking about assertiveness. I am wiped now and my arms feel I have my iron skeleton. DH had to take the DCs out to meet DSD but he'd left the heater on in our room for me so I went to bed, turned the electric sheet on and read for a couple of hours. I hardly ever go to bed in the day and I try not to get into bad habits but this relapse is bad so I'm letting myself ATM.
I've fallen off the Graded Exercise Therapy wagon for a few days - the idea is that when you have a setback, you keep doing your GET if it's a CFS related setback, but you can rest if it's an extra illness on top of it. I decided to start again today and it was only 2 minutes but fucking hell it hurt! I will keep on with it though as although I'm not expecting it to cure me I do think it will help my fitness.