Chances of loose skin shrinking naturally?

So i was really obese and i decided i needed to change that, i was 250 lbs at my highest weight and im at 190 lbs right now. I'm a guy, 15 years old (almost 16) and im around 5'11"-6' tall. i lost 60 pounds over the course of about 7 months. I didn't necessarily achieve this weight loss in the healthiest way, i ate very little and i did cardio exercise every day for around an hour. I admit i did loose the weight pretty fast and i have done my research and from what Ive read, the faster you loose weight the less likely it is to shrink back. when i stand up my skin isn't noticeably saggy (unless you pull it) but if im sitting it folds in on itself. When i was really fat my stomach had like hard fat (if that makes sense?) and now its very very squishy. I can actually feel my abs now and i can sorta tell that there is defiantly a six pack under there however its not visible through the skin. Also, my arms especially have a lot of loose skin and i can pull a good 3 inches of skin on my arm. Im sure ive lost quite a bit of muscle with my weight loss as well, since i was able to bench 185 lbs at one point (max) now i can barely do 3 reps of 135 lbs. Im not focusing on weight loss anymore, instead i started p90x (Day 8!) Im doing everything i can, im even following the p90x nutrition guide somewhat (it tells me i should be getting 2800 calories a day although that's alot for me so im only eating like 2400 a day) My question is, if my skin will go back how long would that take? Also (this is kinda embarrassing) but one of my pecs is lower than the other one, it was like this even when i was over weight. Is there anything i can do to fix that without surgery as well? It looks weird and id like it to be normal but i try not to let it bother me so i still will take off my shirt but id much rather have it look normal.