Thanks both!
Yeah, I was thinking whether it could be that I am getting ill, but so far I feel OK (apart from the headaches and nauseousness from high blood sugar!).
Yes, there has been a change of routine exercise wise as I am quite active in my job and I have been on leave for Christmas, but I have been doing a lot more exercise (walking, running etc) than I normally would during the week to make up for it and I have not seen this big of a jump before when doing the same thing.
Ah, thats interesting about the correction doses, I will bare that in mind in future. I have been doing lots of checks and correcting, it is so frustrating and I am absolutely shattered now as it is taking me until 2-3am to get it back down! I've also been eating less carbs the last few days to try and sort it out, but to no avail!
Thank you very much both, some things to think about!