Hi Cah-Ching,
I know exactly how you are feeling as I was there myself often enough all of last year.
Cutting down on carbs, increasing my water intake and easing myself into SSing is how I got back on.
Also it helps to think long term and to focus on the here and now and not beat yourself up for failing as that just keeps you trapped.
Each time you have a slip pick yourself up and move forward, don't dwell on it as that leads to feelings of doom and gloom and usually is what leads to throwing in the towel and that "all or nothing attitude" comes out to play.
I look at my weight loss as a journey...
Just like when I go out for a long walk, if I trip up and have a small fall I don't go back home and start again from my own front door. I pick myself up and dust myself down and keep going knowing that I will reach my destination eventually, may not be exactly as how I timed it, but I know I will get there.
And so can you
Love Mini xxx