Hey Jen - not much more I can add to what Kate's posted already.
In regards to the spark - that's really only something that can come from within, much like motivation.
Having that list of goals as to why you want to lose weight is one key thing you can do to have on stand by when you're going through a period of doubt or low motivation.
My main motivation spark when its low is knowing how good I'll feel when I've either lost weight healthily (believe me, I once lost 10kg on a diet of raison toast and chardonnay and it wasn't very good...) or I've gone to that exercise class or gone for a run and feel pumped for doing so.
I'm sorry to hear you're finding yourself in a stressful situation at the moment. If there's anything you can do to reduce the stress, grab it with 2 hands.
We're here for you, Jen
Just keep moving! And don't be lazy...
SW: 74.3kg - 1/1/09
CW: 71.1kg - 3/5/09