sorry you're having sleeping trouble Qiutforme - if you're concerned maybe you can speak with your Dr?
Here are some common sense tips that might help too:
Insomnia? 42 Simple Tips to Help You Get to Sleep - Insomnia treatment, cures
As for the wedding, if you're already feeling like you drinking there is a forgone conclusion - I wouldn't go.
You have over a month to think of something fun and sober to do for NYE
D