Keep up the good work mate. Chronic Fatigue is a total bastard, I suffered from it for almost 4 months at the back end of 2008, and to be honest, it very nearly destroyed me!
What got me back together funnily enough was riding bikes. I started off relatively slowly, like yourself, but within a month or so I was getting out 2 or 3 times a week for a couple of hours at least. And because I'd missed riding so much, and I could feel what it was doing for my health, riding my bike became my main excitement for a long time. It totally rejuvenated my love of riding bikes…
If I'm honest, I don't think I've fully got over it even now as every time I get ill, it affects me quite a lot more than the average person, but that said perhaps I'm only saying that now as I'm currently off work ill. But that is for the first time in nearly 12 months, and my fitness is better than it has been since I was about 16 right now (and I'm fast approaching my 30th).
Don't underestimate the good feeling you get from exercise, it REALLY makes a difference, even if it's only a few km on the bike at a very slow pace…