Rengar Jungling

How do you jungle Rengar? I tried following this guide: http://www.mobafire.com/league-of-legends/build/season-7-thrill-of-the-hunt-indepth-pro-rengar-guide-456075 But when I try clearing the 2nd camp, I'm near death. All the time when I try to clear camps, I'm near death. I like the champ, but his clear/sustain is atrocious. I don't have enough HP to gank or to keep farming camps.