Is being a fat bride going to be as horrible as I think it is? Is it worth a crash diet and exercise plan?

You can safely lose about 20lbs in 2 months, that is 10% of your body weight. It is not too late to start safely trying to lose weight before the wedding. Trust me, 20 lbs will make a world of difference to your self esteem and you will be doing it safely. Also ask your photographer to make sure he sets up the shots so that you are in the most flattering position, lighting etc so you will not look heavy. The pictures your mom took in the fitting room are under the worst possible conditions, superbright lights, no make-up or styled hair, an inexperienced photographer. You will look so much better on the actual day. Good Luck!!