Oh bloody hell. Any programme that reduces calories will help you loose weight - it doesn’t matter a jot if its Slimming world or weight watchers or Low carb or intermittent fasting or noon or second nature or just calorie counting.
What does matter is it’s sustainable for you so you can keep doing it in a moderated form after you loose the weight so you don’t regain.
OP, you are deffo not the only person who needs to loose lots of weight and it can be done although the evidence says that people who loose a lot and keep it off do so by having a real lifestyle change . Exercise is great for this - and really important for mental health - so you should do it - but loosing weight is 90% diet.
You need to create a calorie deficit. The easiest way to start learning about this is to download an app like my fitness pal or nutracheck (they do free versions) add in your details and your goals and they will suggest a calorie allowance for you. As an experiment for a week or two just add in what you are eating, and start to see how you can adjust it.
Do some reading and research to see if there’s a programme you might like to do, or if you just want to adjust your current diet.
Keeping off the weight is arguably a bigger challenge than loosing it, so it needs to be a programme you can do long term. Two things to ask yourself - Can I see myself doing this in 5 years time? - Would I want my teen daughter to do it?
To understand more about calorie deficit take a look at the Fitness Chef on instagram. He also wrote a good book which you’ll be able to get from the library which is really useful if you just want to adjust what you eat anyway. James’ Smith’s not a diet book is also useful in this space.
Rangan Chatterjee has a book called loose weight feel great which is not a diet but a guide to the principles of weight loss and healthy lifestyle that also explores why some people find it hard to loose weight.
If you think you have issues with emotional eating, Shahroo Izadi’s The Last Diet is really helpful.
Elizabeth Benton’s Chasing Cupcakes is a good memoir of someone who succeeded in loosing a lot of weight.
If you go to your GP you might find they have support groups or offer free gym membership.
Any sensible diet programme will work, as Will using an app to adjust the calories of your current diet - it’s just about finding the right programme for you.