Rapid weight loss means loose skin because your skin can't keep up with the rate of fat loss. Focus on eating healthy. Lots of fruits and vegetables. Simply by being more active, you can burn calories without traditional exercise. Watch less tv so you are forced to move more, take stairs more often than escalators, park further away from buildings, etc.
You have to get out of the fast weight loss mindset. You didn't gain the weight overnight. And, you won't lose it overnight.