My husband and I are renewing in 2015 for our 10th. I have gained about 50 pounds since he and I got married and I have my dream wedding in mind for our renewal which includes me at 160 in a empire/mermaid 1940s style wedding dress for our "Vintage Hollywood" themed wedding. I've been where you are. I did really good about two years ago then fell off the wagon. I had lost 20 pounds only to put it back on in the snap of a finger. My husband was in the Marine Corps, but even he has put on weight since our wedding.
Start small.....make goals that can be accomplished day to day.
Have your fiance (if you are able to) write you little motivational post its and post them for you to see. (That way you know that you have his support)
Get a workout buddy. My husband and mom are mine.
Find a fun way to bring the fun back into your work out regime. Jump rope, double dutch, play basketball, etc. Think of all the active things you did as a child and do them. (Jennifer Hudson uses this method).
Keep a journal. Use it to track your food, exercise, appointments for weddings, and planning.
Post motivators. If you haven't found your dress yet, you can put pictures of the dress you want on your fridge that way if you want to snack, you have a visual to keep you on track.
Keep healthy snacks with you.
And if you need anything, you can message me.