Hello OP. I can feel the emotion behind your words and understand as I have been in a similar place, repeatedly, over the years.
A five stone loss in nine months is on the one hand a truly tremendous achievement and demonstrates that you have the determination to make positive changes. However, it is a lot in a short space of time.
I read 'Why We Eat Too Much' by Dr Andrew Jenkinson and joined the threads of the same name on here.
Jenkinson explains that diets don't work because they gradually re set your body's weight set-point higher and higher, so you are constantly struggling against your body's efforts to regain the lost weight.
Scientists are now understanding that genetics do play a big role in all this, so that some people really can over indulge without gaining weight, and others don't.
Other insights from the Jenkinson book:
Our highly processed western diets, high in sugar and veg oil are bad for us.
Fat is not the demon it was once thought to be. Sugar is.
Extreme calorie restriction is not the way to go for sustained weight loss.
I've lost three stone ( again) but over 12 months, with one more to go to reach healthy BMI. I've done this by cooking from scratch, and largely eliminating wheat, sugar and veg oil from my diet.
This gradual approach has been better for me as I find moderation difficult ( a personality thing) and, like you have a tendency to self-sabotage.
Here's my Fitbit graph which largely illustrates Jenkinson's point I think. It's from July so that line is a bit lower now - the last few pounds are proving hard to shift, but I expected that, and it will take as long as it takes.