I think its probably the fear of failure and finally getting it right that's holding you back - but you have to love yourself!
I know exactly what you mean, I've got a great job, great partner, I'm comfortable and I love my life - but I still have in the back of my head 'but I'm still fat' which is ridiculous! We're denying ourselves happiness and its just not right anymore.
If you get through today, from the sound of it, you're further on than you have been in a long time, and if you've done day 1 and 2, why not day 3 and 4?!