I usually stay away from the gym if I have a cold...mostly not to spread it around further.I just go outside to a football field and run sprints with a 35lbs vest.
It s funny in that I drag ass bad to get there but once I take off and run 100 yards it all seems good to go. But the worst ever is when the temp is 99F and the humidity is 98%.AND you have a cold? I hate that more than anything.I doubt that you lost anything that won't come back in one workout. Sometimes the mirror plays tricks on us.
You have been down that road before I am sure.
Just crank up some howlin wolf...hwy 49.
https://www.youtube.com/watch?v=zNZReIDuEkE See jake ain't the only blues expert...lol. How about Howlin Wold teaching eric clapton.
https://www.youtube.com/watch?v=qFMDmSglfc0