I'd try 100 for the first half of the week then 200 for the second half. I think 200 right away is a little too drastic. Your metabolism will need time to adjust. That's just my opinion though - it's such a personal thing since it's your wedding I don't want to advice something that has so much hanging on it!
I know what you mean about freaking out about small fluctuations on the scale, but if you know your body and know that these are only fluctuations then I think daily weighs should be encouraged. You have to learn to face the scale even when it won't tell you 'good job'. Sometimes the scale needs to reprimand you to get you back on track. I think sometimes negative reinforcement is good for us. Like 'ok Lucy, you had a lovely birthday meal last night, but it's made you gain a few pounds" and that gives me an indication of what my eating habits over the next few days should be.
I have a weigh daily*and have a weekly 'official weigh-in' day. Like yourself, I know that not everyone is for the daily weigh in, as some will see it as utter*disappointment if the scale shows a gain. You shouldn't see this as bad news or a reason to panic. This scale is information and information is power.
If you are logging your calories and exercise, this daily weigh in can tell you how certain foods or different workout programs*are impacting your weight and trigger you to choose differently (both good and bad) in future circumstances. When you only weigh in once a week, it can be harder to pinpoint the issue that might be causing the problem. Like I know if I eat lots of salty foods then I retain water like crazy the next day. Or when I start a new exercise program I retain water.
I do have a danger zone though. I allow myself a weight window of 3lb of fluctuation and there's no panicking if I stay within that zone. This helps me be at ease with the normal fluctuations and be able to clearly see when it's time to home things in.
I was up 1 pound this morning. Six months ago this would have caused me to freak out, lower calories and work out like crazy.* It was a mental barrier to break. I think you have to become an expert of your body. You have to know that you can't suddenly be 3lb heavier one day than you were 20 hours before.
I think it's good to weight daily and walk the line of the scale every day because when you do, you are no longer a victim of the scale. It's almost like "Hey you, even if you say I've gained 2lb since yesterday, I know it's only water and I'm not gonna be discouraged"
The scale isn't the main tool in all weight loss, but if you use it correctly, it can most certainly be the most important