OP, my story is similar to yours, I was older, as I'd just let it go on for so long. I got to the point where my weight was going to kill me, one small thing after another going wrong, including diabetes. I'd already had radiation for my thyroid condition and then what really frightened me was a scare with liver cancer.
I saw a random GP at a health centre (I'm not in the UK) and he gently asked if I'd ever considered weight loss surgery. I hadn't. I'd seen TV shows with weight loss stories, but somehow, not connected the dots to me.
I was 117kg and I'm only 155cm if I stretch a lot. I used to plan my days around meals, where to park and how little I could walk as everything hurt. My whole life I had been hungry, crazy hungry. I know I was eating too much, but sometimes after even what I knew was a huge meal, I was still hungry. I knew that wasn't right, but didn't know what to do about it. Like most big people, I'd tried every diet. I'd maybe lose a little and then put double back on.
The day the GP mentioned weight loss surgery, I knew it was the lifeline I needed and I knew I had to make it work, or die.
I came home and cried, talked to my supportive husband and cried, phoned the one friend who I know had surgery a few years before and cried and I found the weight loss surgery threads on Mumsnet and read every word (they were at the end of Thread 2 back then).
The day I saw that GP, he started me on Metformin and it helped a little with controlling blood sugar and I waited to see the weight loss surgeon. She was amazing, never made me feel bad, she was just supportive. She said if I had surgery I would probably lose around 30kg. That would have left me still seriously obese, but not in the 'going to die' range. So I booked a date four months later for surgery. It could have been sooner, but that's what fitted in with work and time off for me.
Surgery has been nothing but life changing, in all the best ways. I lost 53kg and have maintained that relatively easily. Also, for the first time in my life, I'm not hungry! This sounds silly, but it's quite a revelation not to feel hunger (at least, not often). The surgeon explained that the part of the stomach they take away during Gastric Sleeve surgery is the part where the hunger hormone, Ghrelin, is produced. All those years of diets, Weight Watchers, special programs, I'd never even heard of Ghrelin. This annoys me as I feel like the sooner obesity is treated as a medical issue and not a laziness issue the better.
The rest of my family were all pretty normal sized and we did a lot of socialising around food. I made a conscious decision that this wouldn't change. I had my first lunch out with a group of friends just 9 days after surgery. I checked the menu ahead as I was on liquid only for the first two weeks (then puree/soft food). I made sure there was a soup I could eat and had apple juice over ice to feel like I was having a festive drink. I had a great time and went home tired, but feeling so good, it was a hurdle and I'd cleared it.
Now, four years later, I sit very happily at 65kg. I can eat pretty much anything I want, just smaller quantities of it. I can stop when full and if I'm not hungry, I say no thanks to food. And it's not even hard! I don't count calories or anything else, it feels like freedom after dieting for so many years (and failing). I am mindful of what I eat, I do make sure I eat some protein at each meal. If I've had a couple of big days, I might make sure I'm a bit more careful for a few days afterwards, but that's it.
As an example, I rarely eat pizza (just never been a fan), but last night had three decent sized slices of meat lovers for dinner. No regrets. I may have had a couple of small Easter eggs too (I still have a stash), but I didn't then have the biscuits that were offered to everyone. Today, I've had a bacon and egg roll for lunch. I am mindful of carbs generally and also a bacon and egg roll fills me up, so I didn't eat the top bun and I'm typing feeling very full. Some people who have weight loss surgery can't eat this much, but then, there are those who also get into competitive under eating.
Since committing to surgery, I am also a member of a couple of bariatric surgery groups on Facebook for my county and these have been very supportive.
I'm not saying you can't lose weight alone or with drugs (that all appeared after my surgery). Just giving my experience and what worked for me. I just can't imagine that I would have been successful with the new drugs, while still having the part of my tummy producing ghrelin.
I do exercise as well, but not crazily. I have become the annoying person who is happy to walk everywhere and I walk over 15000 steps per day (nobody needs to do this but it suits me) and go to Pilates once a week.
Wishing you all the best with finding something that works for you.
Edited to add: All the body parts that used to hurt no longer hurt! I'm not on metformin, that ceased the day of surgery. Life is great!