A stone and a half is a great deal of weight. When I manage to finish losing 21 pounds you shall hear me shouting with glee all the way to the Channel, and I live several thousand miles away in Chicago.
I commend you for this fabulous feat. Do you mean that it's hard to find support for losing weight on the CI because everyone else seems to be skinny...or because you just don't have access to the materials? I'm a strong proponent of Weight Watchers because it's a simple and easily understandable way to eat healthfully for one's entire life (no matter where you live and using whatever local foods are available), rather than a way to diet fretfully, painfully and expensively for the short term.
If you're interested, ignore the extremely cheesy Duchess of York commercials (perhaps you don't have them in the UK) and seek out a single initial meeting if you can--on the mainland if necessary--through www.weightwatchers.com.
If you don't like the meetings or can't find a regular one in the CI, you can do the program at home once you snag the materials. You really will find it reasonable and livable.
Best of luck to you...hope to hear from you again.