You can't lock Nas up forever - he got the top sentence the judge could pass under the law so anything else needs to be dealt with in terms of civil, not criminal law.

As for the victim getting anything back, the fact that Nas was convicted means that the victim will automatically win any civil case where he tries to get damages. Judging by the nature of his injuries, they will be pretty hefty - the idea with damages is putting the victim back, as far as possible, to their life before the accident. Hopefully, any award will go some way to making up for Naz behaving (surprise surprise) like an arrogant dickhead when he got in his car that day.