Unless you're aiming for Palumboism you won't want to put and mass on your waist. If your belly pouch doesn't go away live with it. I live with stretch marks on my biceps and thighs from growing too fast too. Besides, you've barely had hair on your dick for five years, you've been lifting a year and you're 19 - ie, your natural test is at peak and your IGF-1 levels are more than mine blasting 10iu of GH a day. Lift clean for a few years and forget about your loose skin. Enjoy the lifestyle.