yea I am in kind of a funk also, got one hell of a cold/sinus infection and they always go into my chest which compounds everything, i am on antibiotics.

Two weeks ago i did 155 miles, last week two rides for a total of 55 miles, still kind of feeling the blah's.

So what i usually do is just go out and spin in a recovery type ride, keeping the speed around 17-20 mph, no sprints no hard jams up any of these so called rolling hills here in Texas, or i go to the gym and do some lifting.
since I plan on riding today the computer stays off as well as the heart rate monitor, it is about 100 degrees here in texas today so it will only be about 23 miles.
for me any ride is better than no rides.
Hang in there, get some rays and just do a slow easy ride with some miles