Premature wrinkles. Reverse any damage?

I am 16 years old, from September 2016 I have been gaining many wrinkles. I had hardly any in September, but noticed them appearing under my eyes. It is now May. I have wrinkles all over my forehead, around my mouth, under my eyes, on my eyelids, all over my hands, and upon pinching the skin on my legs, arms of stomach area the wrinkled appearance of the skin can be seen. I have been stressed since November, but not extreme stress. I sleep very well, drink a lot of water and eat very healthy. However, I have not been truly happy since August. The wrinkles ARE considerable, prominent, and I look very different. I have gained weight, about 10 pounds since July last year. I look very very aged. Please help me on how to possibly prevent these wrinkles and reverse any damage? I do not exercise at all, I sit at my desk all day, and have been sad for a long while. Recently my diet is not too good, but sleep and water intake is perfect. I am aware about free radical damage to cells.