Well done, Poppy, you've conquered part of that mountain already, just little steps and you'll soon be there.
I lost 175lbs a few years ago on Lighterlife and the feeling was amazing, the problem was though that it came off in 12 months and during that time I never cheated once so I didn't eat any food at all so when I started moving back into eating my issues with food hadn't really been dealt with. The plan is much better now like CD with Add A Meal because you still lose the weight but you are also dealing with food so it should be easier when you move into maintenance.
i have 200lbs to lose this time so I've decided to do it with SW so that I am also addressing my food issues and accepting that it won't come off so quickly.
I hope all goes well for you, just remember to keep drinking that water, it's like a magic fat melting potion!
WG x