Nice progress m8. Skin should mostly shrink back on its own, especially since you're so young, it'll just take time. Give it another 6 months or so and see if you don't see improvement. Some of it might not since you were so massively overweight, and if so, your only real options are surgery or just getting swole enough to fill it out again.
That being said, shave that fucking dead rat off your face, man, Jesus.