Yes you can lose 30 pounds in 30 days of fasting but you don't have 30 days to fast. I'm assuming you're planning to eat a three course meal at the wedding with no thought for your health at all as is traditional and desirable at such events. To do that after a thirty day fast would be dangerous.
Fast for the next 15 days and break that fast with raw fruit for a week after that then add raw salads and progressively add more cooked/processed foods to your salads until the wedding. If you eat minimal amounts during your refeeding and stick to fruit for breakfast and small salad meals when not eating fruit during the day you will have amazing results but safely.