Thanks everyone, it helps to read your replies.

I have a GP appointment in a couple of days and will raise the symptoms with her. In the past I've found she tends to dismiss the fatigue as being normal - that I am overdoing my sport (absolutely not these days), or when I was unemployed that looking for work is tiring. I'm thinking this time she may say it's because I work a physical job but we'll see.

The SSRI did help my mood but it made me 'slow' and it didn't cure the fatigue, I think if I were sad I would consider going back on but not so sure about for lack of energy.