Gin- welcome aboard!
My tuppence-worth is Gillian Riley and her book 'Eating Less'. It is by no means a diet as in Day one, fruit salad and 52g of Special K for breakfast etc etc; it is a re-examination of why we overeat and why, once we go off the prescriptive diet we regain the weight.
It's hard in that it isn't prescriptive, there's no eat this, don't eat that. It's all about looking into ourselves as to why we can't stop once that first biscuit crosses our lips. So there's some soul searching. There's also a 'ban' on the use of scales, because Gillian feels that we need to want to lose weight for ourselves, our health, our self-esteem, but weekly weigh ins point towards the obvious 'what I look like to other people'- ie we measure our worth by others opinion. A happy by-product of eating healthily and mindfully for ourselves is weight loss.
Of course, she does issue caveats regarding what we should be eating but in my opinion, there aren't many women who genuinely don't realise that an apple is a better choice than a slice of pizza!
So the upside is nothing is banned, the flip side is before we choose what we will eat , we need to pay heed to what the consequences will be, like feeling disgusted with ourselves, feeling bloated, feeling like a failure. We have to take responsibility. In this way we might decide that actually, I choose not to feel that way, therefore I won't eat the pizza (or I will eat a small slice then leave the rest), I will choose something that will enhance my sense of control, of well being, of self-esteem.
It's my opinion that habits formed by decades of over eating (or poor food choices, or absolutely no interest in exercise) can't be undone in a sustainable way, overnight. I wouldn't join a gym, for example, because I can't make time for it to become a permanent part of my life, but I can walk vigorously around the block 4 times a week, say.
Look up GR on Amazon. There are several people following her on this board with loads of good advice, and some seem to be successfully combining her with Paul McKenna, as both ideologies (note I haven't said 'diets'!) work on your mindset as the key to bringing your eating back under control.
Your deciding that Enough is Enough is the first step, well done. Best of luck and keep coming back here!