A Belated Hello, plus Snack Help

Hello there, my name's Elsie, I'm 26 and I'm from Yorkshire. I actually joined MFP about 3 months ago and have managed to lose roughly 1.5stones which is great but I've hit a definite rut/plateau now. I'm trying to lose the 3-4stones I put on whilst being ill/on various meds.
I'm looking for more people to chat to and keep me motivated. I'm going to try and lose 8lbs by Christmas. I keep oscillating between 201lbs and 209lbs. So I'd like to try and get to 200lb by the 25th.
I'm looking for ideas for healthy snacks, that aren't boring and can be whipped up quickly and cheaply at home. Any thoughts or suggestions? What are your top tips for getting over a plateau?

I've got a few medical problems at the moment and so am not always able to exercise, although I try and do some sit ups or something each day. I've got Jillian Michael's 30 Day Shred and plan on restarting that next week, as well as Fight Fat and Boost Metabolism which I do sets from. Any other good exercise ideas for someone who isn't always as energetic as they need to be?