Every single person that I know on SW has goen through this, and I've been a member for 5 years, so I've seen a lot of people go through it, and been through it more times than I can count myself!
If you want to keep yourself filled, try to eat more protein foods as well as more speed. The protein keeps you filled up, and the speed helps with your losses.
I'm finding that I'm doing the same sort of thing as you, especially this weekend, I've eaten more syns that I should have and I knew exactly what I was doing when I ate every single one of them, I ust didn't stop myself.
But because of that, I've made a massive SP soup for this week, tons of veg (carrots, swede, broccoli, green beans, peppers, and a couple more I can't think of!) with some lentils (the protein side)
This will keep me fuller during the rest of the afternoon, and will help speed up my losses for next week.
We talked about the whole something that has syns rather than speed foods the other week in group, and one lady had a great point.
When you're sat at home, and you 'want' something to eat, have an apple or some other piece of fruit sat in your eye line and ask yourself are you hungry enough to eat the apple. If the answer is no, you obviously aren't hungry, you're just eating from boredom or something.
If the family event isn't a sit down meal and is more of a buffett, then I would eat something before I went to reduce the temptation to fill up on whatever is there that could send you off track.
You will get there hun, it just takes some will power to avoid those very tempting things that don't help us in losing weight!
Good luck hun, you can do it!!