I first did SW in 2011 at 19st 1lb. Like you I was 34. I'm also a similar height at 5' 4". I had tried Weight Watchers, Atkins, Cabbage Soup diet (yuk!) and various "starve yourself for 2 weeks and lose a stone" extremism, and failed at all of them. I too felt absolutely awful about myself, I had completely let myself go. I pretended I didn't care, but deep down I was crying.
I joined classes and lost 5 stone in 8 months. SW really is brilliant, because you really can eat everything you love. It's about changing the way you eat them, and eating some things in moderation. I don't think of it as a diet, I think of it as a healthy lifestyle change.
Don't think of it as a quick fix, it isn't. This isn't Lighter Life, you won't have to drink milkshakes, stick to stupidly strict rules and lose 5 stone in 3 months. You have to think of SW as a re-education, a long term change to the way you eat, so you can adopt good eating habits and be healthy for the rest of your life. And that's the really great thing about SW. It helps you have a life! You can go out. Drink. Eat Curry, or Chinese, or chips. And still lose weight and go on to maintain your target weight healthily.
With 4 stone to go until my target weight of 10 stone, sadly in late 2011 my life fell apart and I went through a divorce, so I stopped SW, but those good healthy eating habits stayed with me and although I did regain 1st 12lbs I am quite proud that I didn't just put the whole lot back on again and I know that the healthy eating 'education' slimming world gave me helped tremendously with that.
So now I'm back on the plan, first to lose that 1st 12lbs again, and then to tackle that other 4 stone!
Take a look at the inspirational photos thread, they always help me when I'm struggling. They did it, and we can too