Returning to full time work

For the last six months I have been ill following a virus (which felt just like an ordinary dose of the flu), which I have been unable to recover from.  The Doctors are calling it post viral fatigue syndrome, but have not been able to offer any treatment other than rest and gentle exercise.  I have been to accupuncurists, naturophaths, remedial masseurs, psychologists, etc in a vain attempt to get myself well again.  Despite having made numerous attempts to return to work when I thought I was well enough to handle it, I have been unable to string together more than a couple of days (I work as an Executive Assistant to the CEO of a corporation - a job which I love) without relapsing with a vengence.  My CEO has been very understanding up until now and has employed temps to cover my absence, but understandably wants to know when I will be able to return to work full time.  Has anyone else managed a successful return to work?  I would be grateful to hear how you achieved this.

 I was diag with fibromylgia and chronic fatigue in 2004.  I took off work for 18 months (teacher)  I returned to work against my husband and drs advice.  But I had to try.  I have now been working for 5 years.  It is the toughest thing I do every day....BUT I really think I am healthier because I work.  During summers I relapse due to not "getting out".  In the mornings during the school year  ...5AM....I PUSH to get out of bed.  I MAKE myself ignore the fatigue and pain.  By about 9 AM I am so glad I am at work.  I really know it is best for me as during the summer I do not have to push.  Hope this helps