@Gloucestergirl and @flashy158 - Do you currently keep an expanded bllods diary? By expanded, I mean to include what you eat and drink, throughout the day, and how you feel, meaning off-colour/stress/insomia or whatever?
That sort of comprehensive record keeping could provide you with some clues.
I only keep a record of my blood levels for the nurse, i keep getting keytone warnings on my meter, they are sending me to hospital to get it sorted and hopefully back on track.