If your goal is losing weight before a wedding and find your motivation lacking, look around at others on the guest list and find a weight loss crew. Others who live near you and already know you personally can be great support to help you reach your goal, and since they are likely aiming for similar goals you can be a big motivation to them as well.
Just letting others know you are attempting losing weight before a wedding will open the door to find out about others who are as well. Once the group is identified it is up to you how far you take it. From a pat on the back and a "you can do it" in passing to meeting at the park to workout together, there are lots of ways to support one another.
It is important on any weight loss journey to have someone you can call in a bad moment who will give you straight advice and help you make the best choices for your goal of losing weight before a wedding and your overall health in the long term as well. If you can find a walking buddy or gym partner they can hold you accountable.