I know this is dangerous, but will I lose the weight?

I'm 135 pounds and I'm going to the beach in 8 days! I have so much jiggling fat all over my body and it's because I love food, absolutely love it. I eat about 3000 calories a day every day and don't exercise. If I only eat 1000 calories every day for the next 8 days, how much weight will I lose and will some of it be fat? I will be going for 30 minute walks for the next 8 days also. I know this is dangerous but I just want to look good for the beach, I know I'll gain it back but how much will I lose? Will some of it be fat?