Thanks for replies.
I'm a PPL......so it's not a fear of flying! Through my PPL I was fine, perhaps because of regular flying, perhaps because of the safety net of being a student.
I've had a busy couple of years so the number and duration of flights have been going in the wrong direction so I think this is where it stems from. I think I also need to get out out of the habit of the familiarity of the local bimble !