Hey belfie! Haven't seen you round for ages!

Well I went to buy a dress online last night, only to find I'm about 10cm too big for their largest size (hips and tummy)...then this morning I have put on a kilo and a half I have to stop eating so badly.
I can do this.
I will do this.
I want to do this.
Why the hell do I keep sabotaging myself? What is wrong with me?