I'm with Yuckystuff...seems pretty likely it's not real...at least not as told in the video. Parents don't know where their 17-year-old kid is for three days? Shotgun blast to the chest, and he only has a relatively small vertical scar? Shotgun fired near his head, and it didn't open his brain case?
That last one: near the muzzle of a firearm, the expanding gases are at least as dangerous as the projectile/s. If, as described in the vid, he had the barrel placed against his head and was able to push it aside yet still take some pellets, at that minimal distance the blast would split his skull. I doubt he would have survived that one, even if he could have survived his other injuries. Likely the shotgun was a sawed-off, which means the charge would have less barrel length to contain the explosive blast before reaching the muzzle.
Perhaps the kid was shot. Perhaps some components of his story are true, but it is unlikely it happened as dramatically as told.