Saggy Skin Worries

chanii_

I'm 5'5, age 20 and weigh 215lbs(just over 15st). So I've motivated myself to lose weight, or rather the the fact im going on holiday with a load of skinny girls in August has motivated me to finally lose weight and I just generally be a healthier person. I'm doing it the right way, I've started eating around 1, 500 a day and I'm doing cardio and weights at the gym. However I only have 5 months and it's not so much I want to lose 75lbs (I don't mind swapping fat weight for muscle weight) but I want to look good. So I'm debating on cutting down my calories to around 1,000 for 2 weeks out of the months. However I've scared myself into thinking that skimping on calories will make you have saggy skin. I'm hoping at 20 I still have some elasticity in my skin but it has been streched since I was about 13 I just want to know if I lost about 70lbs this short space of time will I end up with saggy skin for the rest of my life? Would that amount of weight be too much too soon or will exercising help my skin bounce back? I'd rather not be the whale on the beach but... I don't want to rush my body and leave it in a mess for the rest of my life. Any advice/ personal experience on this would be great.