Hi poppy,
Welcome to the forum!
Your BG is likely to be up and down while your own cells are still firing, and they are likely to be more sporadic as they start to burn out completely, what is referred to as the 'honeymoon period'. I was diagnosed in Jan 2009, and went through the honeymoon period for a few months. It lulls you into a false sense of security as you think you can eat things without it having any (or much) effect on your BG, but then all of a sudden it does!
I would keep close links with your diabetic team and don't be afraid to get in touch for advice. My DSN was (and still is) always on the end of the phone and ready to give advice for how best to manage watever was happening for me. It sounds bizarre, but once the cells have finally died off and you are fully reliant on the insulin you give yourself, it really is much easier to control, honest! Keeping a record of food/activity/BG and insulin will prove invaluable, and help you work out what effect all of these things have on you and how you manage the condition to live your life as you choose, living life with it rather than around it.
Good luck with it all - enjoy the journey!
Jen