Hi Anne,
I think this is a common problem cos I did exactly the same! After about 4 months I returned to work, as a primary school teacher, on a phased return. Within 6 weeks I was back at full time hours. I lasted 3 months before I was off for 5 months with exactly the same symptoms as you. When I eventually felt like I could return I went back pt (as advised by OH) but still on a phased return because school wanted me back to ft ASAP, I lasted 3 weeks and then was back off again. After being off for 3 months and having sen the consultant and many docs, I was forced out of teaching as they thought that it was far too much for me and suspected that it would be forever.
I still work ft in education research and still find it very difficult to carry on. As you may know I had lots of trouble with my company over my illness and supposedly other reasons. I eventually took a demotion to keep them quiet. I still get wiped out one weekend in about three with exactly the same symptoms.
Since mum has been in hospital these have been worse but I have another docs appt for Tuesday. You are definitely not alone in wanting to get back to 'normality' and overdoing it. I wish I had your work colleagues though
Love and hugs
Laura
xx