Stick it out. My doctor didn't allow anything but broth, jello, sugar-free popsicles and sf drinks (no carbonation or caffeine). He had me on it 11 days, just short of two weeks. It's tough I know. I just finished it on Friday.
I feel down sometimes too. I am trying not to think too far ahead or behind. I am trying to stick to the diet as closely as I can because I need to make this change for myself. My health is ok but needs to be better so I can live to retire and enjoy my family more. There are things I'd like to do with them that at my current weight, I just can't.
I'm sure there are things you want to do for yourself since you decided to have the surgery for a life change. I hope things get better for you soon. Try not to get too discouraged.