Ohdear back in January this year I was a size 24 
and very miserable because I had dieted for decades but it never ever lasted and I felt ashamed, a failure, lazy, stupid etc. I certainly identify with your fears about dieting again because I too felt scared at the prospect of embarking on yet another diet. You see, I knew it would fail.
Then I learned about low carb eating and wondered if it was the answer. I did loads of research over the next couple of months and finally in March decided to commit to cutting out carbs completely (except for certain veg to the tune of 20grams a day) for a month. I didn't want to because I loved my carbs and relied on them to make me feel better, although to be honest they actually made me feel like shit 
.
Anyway, Low Carb High Fat is a way of eating where you get most calories from healthy natural fats like butter, olive oil, animal fats and not refined factory produced oils. The ratio is something like 70%fat 25% protein 5% carbs (vegetables), but this can be adjusted.
I was scared when I started doing it because I had been brought up to eat low fat high carb. It seemed so wrong to eat butter! and add olive oil when cooking! However, the difference it made to the taste of food was incredible and guess what else, Ohdear, the fat I ate made me full for HOURS so I stopped snacking. I only eat when hungry so don't bother with breakfast and I eat less at lunch and dinner because eating fat makes you satiated like nothing else. Seriously.
Apparently carbs can trigger some people (like myself) to want to eat more because our body does not recognise them as food and the "I'm Full" switch doesn't get switched on. This means I used to be able to eat and eat (binge) even when obviously not hungry but I was iyswim.
Does that make sense?
I am now a size 16/14 and my fat% has decreased from 50% to 37% (as of last weekend). This despite eating so much fat every day. The LCHF way of eating (it isn't a diet because I am doing this for ever now, carbs cause me harm and I don't want or need them) has given me a sense of freedom I never dreamed would happen.
I eat delicious foods (bacon! 
), feel full, loads of energy, great skin (complimented the other day), no aches and pains, no snoring. Do some googling and have a look at a site called dietdoctor.com, that's where I started my research.
Don't be afraid to cut the carbs, give it a month, you will be converted. Good luck.