Good luck on your journey. My wife and I were in your shoes not all that long ago. It hit us last year when our son got sick right around his first birthday in late October 2011. We just out of the blue stepped on the scale at the Dr.'s office while waiting, and it both hit us that we really had let ourselves go that far. My bride was just over 180 and I was pushing 270. That was a really shocking day.
We had our wedding on August 4th, and we tipped the scales at 143 and 196 respectively. It took a lot of hard work in the gym, in the kitchen and in balancing out our lives to accommodate for fitness. We didn't get in shape for just our wedding and its photos, but for our lives. We have returned home from our trip to El Salvador (home of our wedding) and fallen right back into our routines of exercise and fairly clean eating, because it was a lifestyle change we had made, not just some fad diet routine to get fit for an occasion.