hugo7 as 36X18 hinted at I'd say the impact has jammed your bar-end into your handlebar (even if only by 1mm or 2) thus restricting your throttle movement. Take it out and see how the throttle action is without it before popping it back in. Your lever although broken is ride-able. File / smooth the rough edges down so it doesn't cut into your hands / gloves and look for a pattern part as a replacement (much cheaper, often just as good). Someone like M&P accessories or similar.
hugo7 as 36X18 hinted at I'd say the impact has jammed your bar-end into your handlebar (even if only by 1mm or 2) thus restricting your throttle movement. Take it out and see how the throttle action is without it before popping it back in. Your lever although broken is ride-able. File / smooth the rough edges down so it doesn't cut into your hands / gloves and look for a pattern part as a replacement (much cheaper, often just as good). Someone like M&P accessories or similar.