Post-viral fatigue, how long does it usually last?

Actually, the doctors aren’t quite sure what I had. It may have been a viral infection or it could have been a bacterial infection. A few of us (family and friends) were thinking swine flu. It’s gone on for over a month and the worst of it’s over. The only thing that I’m dealing with now is that I feel so damn tired. I could easily sleep all day. And, I can’t exert myself all that much (only light Yoga and a short walk outside). I’m getting really tired of this…