Belated condolences about your dog, @WobbleWhenIRun. And well done on further losses @notevenamum1 and @ShopoholicIn.
I finished reading Jenni Murray's book Fat Cow Fat Chance last week. It was a gripping read. The middle section covers what happens hormonally when you lose weight, and it explained a lot for me, in particular why my diets end with me feeling uncontrollably ravenous, as though I've got a monster inside me that needs to eat and eat and eat.
In the final section she writes about why she decided to have surgery. It made me feel a bit worried, tbh, because she was basically saying (as were the medics advising her) that once you're too far down the road of significant weight gain and loss, it's impossible to keep weight off by willpower alone, and without surgical intervention it's always going to be a losing battle.
So I hope I'm not too far gone for it to work because a) I'm terrified about having surgery, b) I wouldn't fit the NHS criteria as my BMI even at my largest is too low, and I don't have a spare £11,000 which is what Jenni paid to have it done privately, and c) the lifelong restrictions around food sound awful.
But it's worth a read, I think, and I recommend it.