How do I prevent getting any more loose skin and get rid of current loose skin?

I am a 16 year old male and have lose 40 pounds within 4 months. Instead of losing the reccomended amounts of 1-3 pounds a week I have been losing 4-5 pounds a week. I started out at 231 I am now 191. I fear I have lost lean muscle tissue in some areas. Even though I have increased protein intake (with bars and shakes) and the amount of resistance training. I also started eating less. Going from 2600 calories making my way gradually to 1900-2000 calories. I also started exercising 2 and a half to 3 hours a day. I feel that I am getting loose skin. Some of it is getting stretchy like a rubberband. Any suggestions or professional opinions welcome!|||Take 1-3 grams of Fish Oil daily. It helps with elasticity. Keep up the good work!|||Well the best thing would be to lose the weight slowly so your skin can adjust itself. You should also take vitamins C, E and Biotin and eat plenty of fruits and vegetables. Also try skin firming lotions that contain Collagen and Elastin