Am I justified to get implants?

I'm 16 (I don't plan on getting surgery until I'm 18) and my sag horribly. They're C cups. The stretch marks are horrible on them as well (very deep). I gained weight on steroids (for asthma) and even though my didn't get bigger when I gained, thee skin started sagging very badly (I can pinch easily 2 inches of skin off each s). I have Grade 3 ptosis (which is the worst amount of sagging you can have). I was originally just going to get them lifted but from what I've seen, a lift causes more scarring than implants and not as pretty results so I'm going to get implants and a lift because my have lost very much volume. I plan to go to a D or DD (I'm tall so I won't turn out looking like Pam Anderson. I know some sag is natural and I wouldn't mind having some sag from bigger . I'm not vain about every little thing on my body but I'd like to be able to look nice when I wear a tank top. Am I justified to get the surgery? Thanks.