Fear of letting go

Hi Brooke,
I need your help understanding the thoughts behind a fear: I must have had it for a very long time but only uncovered quite recently. I did visualizations of myself at my ideal weight. I tried and tried and just wouldn’t see myself being slim. Then, finally, after a few weeks I got there and could even feel for a short second how wonderful it would feel – and then this gigantic fear kicked in. The thought behind it: The moment I’ll be at my ideal weight, I’ll have to die (no more reason to live…the last one of my big goals in life will then be “done” – no more reason to stay). Of course I do know that this thought is nuts and untrue (and no wonder I cannot loose weight) – but it feels like truth. How can I demystify it and feel safe while losing weight? Is it simply repeating again and again that I’m safe and those thoughts are untrue? Or can I do more?
Oh – and thanks so much for your advice on urges – I’m listening to the weight loss program, it’s absolutely fantastic. Thanks so much for all! xxx Claudia