Take it easy jags, I know how lacking motivation can get anyone down, but there's nothing wrong with putting something aside for a while, no need to be hard on yourself about it.
There's plenty of evidence for the relationship between physical exercise and mental well being, so if not cycling try and find something else, there's nothing wrong with a round of golf...
When I'm "off" cycling I go to the gym at least every other day, sometimes have to force myself out the door, but then get a lot from it in a relatively short time.
Whatever you do, just take care of yourself.