Ooohh I'm doing it the other way round to you. We're having the blessing ceremony (wasn't willing to go through an actual Indian wedding but wanted to deflect my Mum from interfering too much with the actual day) in August then getting married in October.
It can be hard to force yourself into having that panic factor. It can help to regularly look at pics of your outfit(s) to remind you what's at stake on those off days.
Teaming up with a buddy and possibly also turning it into a competition can really boost motivation even if you're not naturally competitive. This is what I'm doing with one of my BMs - we're putting in £2 a week as we do our weights and measurements and then whoever loses the most by the wedding gets all the money. I was talking to her boyfriend at the gym last night and apparently I'm currently winning - Wooo! Just need to keep it up now...
Treat yourself - if you do x amount of healthy eating and working out then you can treat yourself to a new top or a massage or whatever else you might like. When you really don't feel like hitting the gym then tell yourself you will work out now and then you're allowed to veg out in front of your favourite TV show but no workout means waiting for the re-run/watching the recorded version.
Set a rule that any dietary deviations (a chocolate bar or take-away for example) will result in x amount of exercise the following day to compensate... with this one you don't have to have the panic factor, it will just take care of itself.