I try and write a post it with my goals on it every day and a reminder of how far I've come since August when I started on Atkins.
One thing I do is try and write one positive thing that I've noticed lately. ie: getting facial features back, pants fitting better etc. to keep me in a positive frame of mind.
I'm not sure if it will help for you Mal, but maybe every time you say something negative you put up something positive with a post it it will help reinforce the habit.
I look at your weight loss and think of you as an inspiration of where I have to go. I started at 297 and am celebrating 235 today, I hope someday to be posting the weight loss you are!