Roxy,
just a thought- are you tracking everything you eat? I think it often makes a huge difference.
I started back on weightwatchers in January 2009 and tracked faithfully. I lost 13 pounds, then hit a plateau until I started cycling. Some things I changed were switching to whole wheat pasta, cutting out most (but not all!) sweets and replacing with more fruit, nuts etc.
I hope that you find something that works for you.
2016 Specialized Ruby Comp disc - Ruby Expert ti 155
2010 Surly Long Haul Trucker - Jett 143